I will still be organising the GTR2 races. We could go back to GTR2 every Sunday or we could try Race Room on Sundays or stay with AC. It depends more on what any potential race organisers would want to do.
It might be a good opportunity to try some Raceroom events using the modern GTs. They are already a great drive and will be receiving quite a significant update shortly. A few of our members already race AC at Core on Sundays so that is potentially going to reduce numbers here (whether we race GTR2, AC or Raceroom).
Personally looking at longer term, I don't think it's a good idea to continue running different sims on alternative Sundays.