I was on my phone when I first reblogged this, so I couldn't comment on the foreshadowing that was going on here (because I don't like to try and write long messages on my phone).
But yes, IMO this was a direct foreshadowing of what Armand actually does towards the end of Memnoch the Devil. And which is when, IMO, that Lestat realises that for every conflicting feeling he has for Armand, he doesn't really want him dead.
But yeah. That failed suicide attempt by Armand at the end of Memnoch is a very important character moment for Armand. He tried to redeem himself for all the sins he had committed up until then by doing it, only to learn that there is no redemption for the things he had done. And there never will be.
I also like that Lestat flat-out tells Armand just to be himself. Because, as I've been saying, what we've seen of Armand these first two seasons has been a mask, and not his full and true self.
In fact... I'd bet the last time Armand was his full and true self was when he was with Daniel in the past. Because, again, that is one of the main points of their relationship during that time. Because before Daniel, everyone saw Armand as a beautiful Botticelli angel and all of that.
Yet, what did Daniel see? He saw an evil creature, a giant insect that had devoured over a million human lives. And Daniel loved him anyway.
And can I also say that is one of the reasons I hate the fanon version of Armand that much of fandom has cooked up? Because even Assad himself said that what Armand wants most is for someone to love him for himself. And the fanon-version and take on Armand is not him. It is, essentially, just another type of mask, only this time one put onto him by other people and not one he put on himself.
But yeah. I will be surprised if the show doesn't do Armand's failed Memnoch suicide attempt at this point. They are signaling it here, IMO, just like they were signaling about Louis' Merrick suicide attempt.
The thing that looks like I got incorrect about both attempts was that I thought Armand's attempt had already happened in the past (because he already knew he was immune to the sun) and that Louis' would happen in the present at the end of Season 2. But now it's looking like that is going to end up being the reverse -- Louis' attempt happened in the past, and Armand's attempt has yet to happen. But will, and likely for the same reason it happened in the books as well.