EXACTLY. Sam, Rolin, and Hannah already said that Lestat IS an unreliable narrator (and that Lestat's far more intentional/deliberate in his unreliability than LOUIS is, because Lestat's NOT suffering from amnesia like Louis did; Lestat's memory's perfectly fine). And Rolin already said that Louis on average was 70 - 85% RIGHT; he's 30% wrong MAXIMUM, even with Armand screwing with his memories and feeding him the wrong information & lying for 77yrs.
So yes, there are things that Lestat definitely can (and needs to!) correct. And a lot of that is directly tied to things Armand told Louis that we KNOW were outright lies. And there are ways to prove that, and corroborate Lestat's versions, by looking at what other witnesses have to say (Gabrielle about the Lioncourts, Nicki & Armand, The Vampire Sam about Armand & Claudia at the Trial, Marius about TWMBK, etc).
BUT, there are things that ONLY Lestat can tell us, cuz he's the only one still alive who was there and who can say anything anymore (wtf went down with him & Nicki, Magnus, Antoinette, Claudia, etc--DEAD people). So yes, there ARE things where we'll have to either take his word for it, OR wait for the show itself to make it clear (enough) that something's not right--outright contradicting him or revealing/revisiting something later. If the latter NEVER happens, we have to assume that it's true--the same way we did when Louis told us about his Dead People (the DPDLs, the Alderman, Tom, Jonah, Miss Lily, Bricks, etc).
There's also the objective truths from AMC's POV as the omniscient narrator. Wrt S1 - S2, everything that's NOT a flashback, and takes place in 2022-present is a REAL scene that happened; even if we the audience don't get to see/hear every single second of it (Daniel in NYC in 1x1, everything that happened in Dubai (Loumand, Daniel, Raglan James & Real Rashid), Louis & Lestat & Felix in NOLA in 2x8, Daniel is a vampire, I Own the Night).
We haven't seen S3 yet, so who knows how Lestat's narrative will unfold, as far as how we'll be able to tell what's all real (past flashbacks, present events) VS what's a hallucination (past or present). Will the documentary be solely candid camera footage & interviews, or will it be more artistic & doctored/avant garde? Where's the music videos, even?
The rest is a messy game of he-said / she-said, where there are multiple POVs describing the same events in different ways. So the ONLY objective truths from the characters are:
what's consistent: what they ALL agree on
objects: physical material evidence that exists in-universe (Claudia's diaries, Lestat (re-)recording Come to Me, all the newspaper articles from NOLA & Paris, all the photos in the Paris Archives, the Trial script(s), the 1973 interview tapes, etc). And even that's not saying that the information stated in them is objectively true (let alone how they're subjectively contextualized/interpreted); only that the FACT is that because the objects exist at all means it's true that something actually happened to create them: (Claudia kept a diary, Lestat recorded a song for Louis after the Ep5 Fight, Louis was a Paris photographer for years (he has photos of Delainey!Claudia, so we know that's what she really looked like; recast aside), the Trail was rigged AF & Armand was the director, the 1st interview was a mess Daniel almost died several times Louis killed himself Armand messed with DanLou's memories, etc).
So yes, just like with Louis, there are things Lestat will say that I'll take him at his word for (because there's no one else TO hear out); and things that I will look for (in)consistencies with (because there's alternate versions/perspectives); and things that I will outright question/reject (because I KNOW something else is afoot).
It's ridiculous to walk into ANY season of this show thinking that the whole thing's a big fat lie; but also that every character is 100% reliable. This show requires turning your brain on; because Rolin Jones is deliberately trying to confuse us with Memory is a Monster / Let the Tale Seduce You to an extent that Anne Rice's books NEVER did.