Naturally, issues should be fixed and all companions should be brought up equally while ensuring the bare-minimum quality standard is maintained across all. Unfortunately however I recommend not expecting Minthara to be treated that way at all since even with updates specifically focusing on companions she gets almost nothing but more bugs.
As an example with the Valentines Update #6 which was all about romance; Shadowheart
(who is the most developed and fleshed out character in the entire game) received new voice lines if you sit on her camp stool, new romantic banter and a community-requested option to hug her at the end of her personal quest (among other additions). Minthara on the other hand to this day still does not even have any romantic greetings at all, no greeting variety, not even a relationship dialogue branch... and numerous other long-lasting issues.
The utter lack of care is quite evident, though she has practically been abandoned even before Early Access launched which is why this has nothing to do with how popular or vocal the community. The community surrounding Minthara has been the most persistent and consistent one to date, continuously pointing out numerous issues, shortcomings, lack of content and outright neglection of her from the earliest days of Early Access up until this very day. I am just one of countless many people who
since Early Access have been pointing out the COLOSSAL imbalance of content and lack of care towards Minthara and the entirety of the "evil" side.
Apart from pretty much all of it falling on deaf ears, it took ages (and several patching attempts) before even her most basic default dialogue became available to players after release, so that's how sad her whole situation.
The attention and care will always be given in this exact order, as it always has been; Good choices > Shadowheart > Lae'zel > Astarion > Gale > Wyll > Karlach > Jaheira > Minsc > Halsin > Evil choices > Minthara.
