She is tucked away in a side room to the main hall of Moonrise Towers. Without exploring the whole of the Towers and making it a point to speak with every single NPC and vendor, a player can absolutely miss speaking to Oblodra.
She is not mentioned by any other NPC on the main objective path as a point of interest either.
She's in a side room, fine, but she constantly yaps about blood and you can hear her talking to herself from quite far away, most people would be curious enough to investigate. Now missing talking to the Absolute while in the Moonrise Towers is way more plausible (cause you gotta go up the ramps and parkour a little bit - I admit, I missed the Brain on my 1st run, but Araj won't freaking shut up about blood hence she is nearly impossible to miss - unless you do what you did and meta game).
Bad excuse.
Also, high approval Astarion confession USED to be impossible to miss too (all you had to do was enter MT and talk to Ketheric and if you were on very high you'd get the 'you are incredible' scene) but in patch 3 it was bound to killing Yurgir for Astarion (after having triggered the part of Raphael's deal with him which you on purpose didn't take him to).
The only thing I can agree on is that Raphael should come and translate Astarion's scars if he was spoken to about it in LL.
But the rest, sorry, no. You metagamed yourself out of the romance sadly.
