Doesn't look that way. RT is winning.
Even still, the support for TB combat is going to be over-inflated because Larian forums are filled with fans of their D:OS games, which are TB games.
Also, since D:OS2 is a recent excellent title, many Larian fans (many of whom might not have played BG) are going to want TB just because it's all they know and they don't want to try something different. At least on the Steam BG3 forums, there is a degree of D:OS2 fans who clearly are not happy that Larian are making anything other than D:OS3, and since they aren't getting D:OS3 right away but are getting BG3, they would like to co-opt BG3 and have it be a reskinned D:OS2. I think those elements of the audience need to be resisted because they are not looking for Baldur's Gate 3 to be Baldur's Gate 3.
Just like it would be selfish and arrogant for Baldur's Gate fans to start demanding D:OS3 use RTwP combat, spiting the fans of the D:OS series, it is also the same when D:OS fans (which I am one of) do the same thing when it comes to BG3. The whole point of announcing Baldur's Gate 3 is to tap into what Baldur's Gate is and means to people, its own legacy and not some other series', and I think it's hard to see how swapping RTwP for TB wouldn't be a bit of a betrayal (and I've already seen that there are those who would call it more than a bit of one). Baldur's Gate 3 is a once-in-a-blue-moon opportunity, or even rarer, and so it would be tragic if it was squandered for the sake of fanservice to a different series.
I love D:OS and its combat system is fun in those games. But, RTwP is also a ton of fun. Both these systems have their places. Baldur's Gate is an iconic RTwP game, and without RTwP it wouldn't really be Baldur's Gate anymore, and with TB combat it would be a semi-clone of D:OS.
Plus, there's Wasteland 3 coming up, and that will have TB combat. So, people who are somehow needing a TB combat game will have their big-title TB combat fix in the same timeframe as when BG3 will release.
Also, Larian will undoubtedly make D:OS3 at some point, maybe after BG3. It would be good for them to expand their skills and do something fresh between D:OS games, which will also keep the TB combat fresher for when they make D:OS3. Making BG3 RTwP will mean that there is larger appeal for another TB game when D:OS3 releases.
The fans who've been loving Baldur's Gate since its release, who've kept its popularity alive, and those who have been waiting for a Baldur's Gate sequel for 2 decades don't deserve a D:OS clone and reskin. I imagine there would be justified anger if Baldur's Gate 3 was not faithful to Baldur's Gate - and RTwP combat is a key aspect of Baldur's Gate's identity.
I'm sure that Larian would like to stretch their creative legs and enjoy doing something different than what they did for their previous two games, themselves, and that they likely would love to show how good they can do RTwP just as they have shown how well they can do TB. Larian have demonstrated their studio to have a high level of skill and creativity, bristling with ideas, and I fully believe there is room in Larian's current and developing expertise to be more than a one-trick pony. Baldur's Gate 3 is a big chance for them to show it once again.
Looking at all aspects, and there are many more than I've mentioned in this post, it would be stupefying to me if Baldur's Gate 3 didn't have RTwP combat. BG has a rich identity, and that RTwP is iconic to it, and I think that anything else wouldn't be the Baldur's Gate that makes the news of BG3 amazing and wonderful for BG's fans. It would be another game - maybe a very good game, but another game all the same, and probably one that should be billed as its own thing and not presented as Baldur's Gate 3.
Larian is a fantastic developer, and D:OS is a fantastic series. I'm sure and certainly hope it will continue to be one when D:OS3 is made. Right now, though Larian are making Baldur's Gate, not D:OS, and I'm looking very forward to a new Baldur's Gate game, and then a new D:OS game afterwards, and not another D:OS game masquerading as a Baldur's Gate game. Let each have their place, and not over-indulge one at the expense of the other.