Soft Brexit – the status quo remains intact, and nothing changes.
Footballers are granted the same special exemptions that are currently given to ‘entertainers’. This means it is easier for them to obtain work permits than other people, and it will not have a huge impact on player movement from the EU.
Hard Brexit: the work permit rules that apply to non-EU players are now used for EU players as well.
I'd say it's not a soft or a hard brexit, it's somewhere in between the two. IIRC, there's lots of different flavours of brexit modelled in the game, which one you'll get you never know, until it happens!