I don't see the issue. Parliament has already I thought passed the legislation to stop us going no-deal and to force the pm to ask for another extension and this automatically becomes law as part of the prorogation process as I understand it? If so a GE now is fine.
A General Election changes that and if he moves the date it can still be forced through I think.
Labour have no motivation for a GE now. Wait 2 months and the Tories will have destroyed themselves by then.