Historically - this is my impression anyway - when a site has its own reviews, TER cuts them off.  (I can think of one obvious exception with respect to our proclivity here!)
Second issue (I'm wild ass guessing) might be that their main revenue, or at least a significant source of their revenue, would be coming from the ladies posting ads on their site.  A discussion board such as you're suggesting might turn off some of the advertisers.  I'd guess it'd be just a source of heat and hassles for them.

Mostly, I rely on TER for this sort of information.  I've not found much value in other review/discussion sites.  (I dearly miss redbook though!)

I suppose someone could mount an effort to create such a discussion board, but dealing with censorship, the law, and all sorts of moderation headaches would, I'd think, make it well to much hassle to sustain.  Like I used to bop around on Reddit, and could kind of imagine a subreddit dedicated to "Discussion of advertisers on tsescorts" but it'd be shut down within days if not hours - even if it was a "private" subreddit.

These days, I seldom bother with ladies who, though they have enticing ads, have little in the way of reputation, which mostly means a nice set of reviews here.  But sometimes I just search this forum and find some gold.  There's a hot looking/sounding one in Oakland who has been tempting me for months/years, but has no reviews, and when I searched the forum here, I found something like "... she doesn't like reviews, but she's pretty awesome!"  So she's on my list now.

I took one for the team just before covid came along, and I ended the review with "... it may be quite a while before I TOFTT again. I'm SO GLAD TER is back!"

I completely agree, tsescorts plus other sites could use discussion boards and more through screening processes for providers. But since their primary income is from people posting ads, many sites don't care about the hobby or hobbyists, just a way to make money from it. There's always been problems with fakes here and there, but since the pandemic it's increased.  

Since the pandemic I've noticed more fakes on tsescorts, but there's also a growing number on Eros and TS4Rent. Plus, more providers advertise a personal site like OnlyFans, JustForFans etc. I think the reason TER has remained among the most legitimate is becasue they only offer reviews, not advertisement. So they're not playing both sides from the middle as many sites are.