Spoiler for constilations and thoughts ons the future
So, Vena and Ryoku are different then any other protoframe. They are more cybernetic versions of warframes then infested versions like the rest. With Pavos in the future becoming a Cephalon, if strongly hinted that future corpus made them. I have a theory on ALL OF THIS.
I think that any future protoframes will not be made by Entrati but Corpus/Paros. I also think, the idea is once we return from Tau, there a time jump. And the world is just not the same anymore. The future happens because the operator and drifter were not there to keep the balance.
Not sure how they accomplish this other then maybe steel path enemies only, or a separation between new and old players or something. But more then likely too, Narmer and Corpus and probably Grineer fight. They had to adance there options like the ones we see in the Zariman, especially the Grineer.
Once Wally is dealt with and Entrati, the universe is still not safe.
So yea, that's my threoy. No more infested protoframes. They might still add more protos but I can see them also slowing down because I am sure it apparent that protoframes are not as interesting to people as they use to be. Not cause of the new warframe talked about in Tennocon, if you know, you know. I don't have proof but I do think the two newest ones did not have a lot sales compared to other protos. I know I didn't buy them.
I think they make a good story to have someone speak for Sirius and Orion and to have the after content, it can't be Sirius and Orion fighting without it breaking the whole goal of the quest.
But yea that's my thoughts and theory. I be ok if there a few more protoframes from corpus or even grineer cause I could see them do barbaric stuff to make one, but otherwise, I good with what we have. No more from Entrati. I don't think it make much sense but I don't know where is story is going so you never know.
Also he left his kitty cause the rain would probably kill the beautiful white baby kitty, and if not the rain, the inhabitants would. So was for her safety more then likely. Pretty sure Kalymos is the one thing he cares about. Maybe not exclusively but who knows.