I can imagine that if (and it's a big IF) any EU flights are affected it will have a knock on effect on all other flights as planes will be in the wrong places, and landing/take off schedules could be affected.
IMO, if anything, it's more likely it will affect your immigration (either way) rather than the actual flight.
But I'd go with the risk as I think it's extremely small.
In theory a shed load could be affected, but as we were never in shengen, and getting through british airports is always a PITA, then no, like Smokie I think air travel will be BAU . (B loody awful usually)