That was anticipated
Two things are predicatable after any "terror" related incident (although in this case, one nutter with a knife does not exactly seem to worth even considering as terror):
1. Right-wing nutters will groundlessly blame it on immigration.
(check - Nuttal and Farage both - later turns out nutter was UK-born and converted to Islam in UK)
2. Home Secretary of time will use it as an excuse to try to get more surveillance powers.
In both cases, there is no basis in evidence for the reaction.