P61 can be a nice addition - eventually. While it will be reasonably popular in the MA, it has very little value for scenarios and special events.
Beaufighter is probably the most significant plane on the allied side that we do not have. Served from 1941 to the end in all theatres of operations, in many roles, so it can participate in numerous special events. The later models are not complete dogs in the MA, and it will have the unique capability of a torpedo fighter-bomber.
Blenheim is interesting for scenarios, but it will be that plane that nobody wants to fly in that scenario...
Meteor is useless for scenarios. It can be an interesting addition to the MA as a 262 alternative/adversary.