It's just a natural result of Gfriend leaving.
They only had 21 staff members in 2019 and half were probably involved with Gfriend, the rest being Trainers and general staff.
But what is more clear is that Source Music might not be debuting a Group in the near future although they could still be training Trainees.
The other speculation is that HYBE could be debuting a GG where HYBE can absorb any loss under a COVID environment while Source Music could likely go under.
So thinking of it more.....
I'm thinking that Source Music could be the central source for recruiting and trainee female talent.