I think the way you think about Heinous/Meteora “getting turned back into a baby” as a form of death is interesting, because of how people usually view it the way it was meant to be seen. Honestly, I agree with your interpretation because BVI DID induce both a bodily reset and ego death onto her.
Plus, I know a character who had a fate that can seen as vaguely similar to what happened to Heinous/Meteora (purely in the sense that the character in question’s problems are resolved by having them essentially become someone else, but in a different way to Heinous/Meteora).
I have been thinking about it over and over again for years, even when I was younger watching her be turned into a baby for the first I felt immensly frustrated.
The worst part to me is how everybody in-universe and in real life considers that fate as being a "good" thing for her, completely disregarding her life and value as her own person. Yes her past was painful and unfair and her current self was a danger to the kingdom, so I can see why the writers took the easy route of resetting her to pretend she can have a good life now, without having to aknowledge the burden of her entire existence, because yeah the writers and the characters (including eclipsa) treated her (very reasonable) crash out as a burden that needed to be stiffled and shoved under a rug.
It's even more disheartening when you take a deeper look into Heinous' character and what she represents. I could go on and on about how well she embodies the struggles and expectations that come with womanhood. She spends her entire life getting abused, restrainging herself and obeying her "mother"s every rule in order to become what a proper woman should be, and the moment she steps out of that mindset and gains a smidge of freedom and autonomy she gets violently punished for expressing three centuries of well earned frustration (cause let me tell you if I were in her shoes I would've been a billion times worse)
This ending is really a slap in the face compared to her character's arc, it clearly criticises misogynistic beliefs only to end up reeinforcing them by replacing the angry old unwomanly hag with an innocent more feminine baby with no autonomy.
People act like this was a good thing for Heinous but really she just suffered the same fate with Eclipsa as she did with St Olga, getting abused and stripped of everything that made her "flawed", because she was too angry and old and violent so she HAD to be fixed for the good of society. And I think the show and the fans won't aknowledge that because it makes Eclipsa (sorry Eclipsa I love you but you literally killed my goat🥀) look bad
She was stripped of ALL her memories, personality, emotions and even her body against her will and you want to make me believe she's not just dead? Not only that but she was also replaced with a more acceptable substitute AGAIN, baby meteora is just festivia 2.0. On top of all of that she's also being forgotten by everybody, globgor never gets to know about his daugther who looked just like him, Eclipsa never aknowledges her daughter who lived a whole 300 years before meeting her, the show itself never aknowledges Heinous again, except for a one off joke about Meteora hating Marco for no reason.
And to me the scene that represents how little the writers cared for Heinous' character later is when Eclipsa says she hopes Meteora doesn't remember anything from before, like ok I see fuck her I guess?? It feels so dehumanizing to see how she's treated as burden and something that they HAD to get rid of. In all her three centuries of existence Heinous was never given a fair chance at a life and even after she's gone it's like she never existed, that's how little she matter to the world, including to her mother
One thing i hate is how the fans and the writer are unwillingly to accept depicting Eclipsa as a morally grey person. I think that would make her character even better and more compelling but no she HAS to be completely innocent and get absolved of any wrond doing for some reason. Like god knows I love a woman with dubious morals (ahem heinous ahem) so I wished they were more willing to aknowledge that Eclipsa does bad things sometimes, and that resetting her daughter was indeed a very very selfish move. And just to be clear, protecting the kingdom from Heinous was not the selfish part, but having meteora resetted into a baby and willingly ignoring her entire existence up to that point, just so she can have her happy end with a normal baby was crazy selfish, and it's the most cruel thing that could happen to Heinous when you take in consideration her past.
The thing is they dont treat what Eclipsa did as a bad thing because they don't treat Heinous as a person deserving of mercy or compassion and I think alot of that stems from mysogny, if Heinous wasn't an old woman I guarantuee you her character would get alot more grace from the fans and the writers