I doubt it would be that easy. Again, the EU will require robust legal oversight and enforcement of rules, subject to ECJ ruling and laws decided solely by EU members. And of course, licenses in the UK will remain under the oversight of the CAA and subject to laws and rules issued by UK ministers (not parliament anymore, they have squandered away their sovereignty). And of course the main reason not to align with EU rules was to diverge from those. It might be in minor matters, or in major matters. And of course, EU rules and laws evolve constantly, there is new secondary law issued by EASA roughly once a month, not completely, but in single issue topics. The UK would have to follow those rules to be considered of the same level, and not only for the moment, but for the future as well. After all, the EU deals with other governments, not professional associations except for lobbying reasons.
And in the end licensing, unlike insurance deals, is about legal government oversight and enforcement. However, personally i would love to se that play out, but i have no high hopes about a construct like that.