I think the market is already there, we know many on the forum love betting in this area, and not even a few, soccer speculators are almost all of them in my opinion, as well as other sports.
There is an obvious market for sports betting, but not all sport betting websites get popular and it also needs much resources channeled to attract players from other platforms.
If we have a good number of existing casino players on playgram somewhat interested in a sports section being added, that will mean there is obvious demand among players who will keep the section running from launch.
The only real way to know if people are interested is to test run it for a period of time and see. It's up to the team to make the final decision.
You are right in fact, the market is highly competitive and nowadays people needs to see some fairness or a kind of promotion to attract their attention. Moreover mos players I mean gamblers always have theirs favourite platform that is more suitable to them, so to attract attention to the site they need to do something extra ordinary to prove to its community that it's worth using or testing the site maybe it could something like free spin, ref bonus, high odd and many more to attract them since the market is extremely competitive for sports betting.