Actually, given that the BEF is smaller than in OTL, perhaps Gamelin will scrap the Breda variant of the Dyle Plan, or will even revert to his Escaut Plan (in which the 7th Army is in reserve)And futhermore part of British army is fighting in Sweden and occupying Norway. So BEF in France is going to be even
smaller than in OTL.
And even if France somhow manage to resist Wehrmacht better thn in OTL it is going to be really hard fight.