Suggestions on beating a Reinhardt/Sym/Mei combo on Capture Point maps?

So, I've seen this combo played a lot in mid plat ELO and it has been a nightmare to deal with. Especially on Hanamura, Eichenwalde & Volskaya. What happens is an intense stare down at choke points for 5 minutes with the attacking team being unable to effectively push, which is incredibly frustrating.

I've tried going Winston/Pharah to get behind and create a distraction, but pushing through that choke usually kills 2 team mates. Any suggestions on how to counter this obnoxious combo?

PS This comp can be legitimate cancer. Abuse it for frelo