From the PL handbook
Appendix 1:
Profitability and Sustainability Rules - Standard Directions
Introduction
1.These Standard Directions have been agreed by Clubs to ensure that any complaint regarding a breach of the Profitability and Sustainability Rules (Rules E.50 to E.55) (a “PSR Complaint”) can be resolved, including any appeal to an Appeal Board, as expeditiously as possible and, absent exceptional circumstances, prior to the 1 June following the submission of the relevant Club’s Annual Accounts (the “Backstop Date”).
2. The League and Clubs recognise and agree that, given the possibility of the imposition of a sporting sanction in the form of a points deduction on any Club found to be in breach of Rules E.50 to E.55 and the desirability (so as to protect the interests of other Clubs) of any such points deduction taking effect in the Season in which the relevant Club’s Annual Accounts are submitted, it is important that clarity is reached regarding any such sanction prior to the subsequent Annual General Meeting. This provides certainty for the League, its Member Clubs and other stakeholders as to the membership of the League in the subsequent Season.
Obviously there are clauses on how they can vary it etc. but it looks like we could argue to have it this year. However, I think the law regarding competitions etc will state that you can't change the rules of the competition after the effect. That's different to ex past facto law imo.