No one wants to play in an unimportant tournament like this a month before the season starts. Every team wants to field their random academy shits, but other teams sent their best players anyway.
ZETA always try to maximize their academy players in offseason tournaments. Remember RBHG last year when Caedye and yatsuka were in? Same thing.
They're just 3 out of 10 players in the system, there's nothing wrong in +rep their experience and exposure considering they'll be in Challengers JP next year.