I think its a stretch to expect someone who’s never heard that phrase or its background context to immediately associate it with a specific set of crimes regarding inciting racial hatred in a particular period of rioting in the UK
Depends what else people have been jailed for in relation to social media posts, dunnit ? The things you mention are the most recent and highest profile that I’m aware of.
If the individual had just said “…than you do for saying something on twitter” (in their workplace,(apparently as some sort of a leader within it), they’d have been a grade A **** and would deserve whatever they had coming – it still implies that calling for, as a specific example, burning down hotels full of asylum seekers is a minor transgression in comparison to (whatever else they said)
If that phrase came to their mind spontaneously then they’d still be a **** but also “guilty” of using a childish term to trivialise the reaction (grade A+, perhaps).
If they used what apparently is a term favoured by Nige, Tommy & chums (I didn’t know) marks them out as whatever is worse than a grade A+ ****.