Around 5% of the population is estimated to be gay. What would surprise me is if JWs were significantly different.
However I do think there are greater incentives for gay JWs to leave these days. Because decades ago mainstream society objected to gay love just as JWs do. So gay JWs might as well have stayed where they were. Nowadays there is a huge gulf between mainstream opinion and JW views on gay love. So the attraction of leaving JWs now is acceptance, freedom and love. No wonder so many gay JWs are leaving these days rather than sticking it out.