I noticed an airbus pm out and back 370/02Oct assigned to an A+ pilot. Gets back around 0045 local Memphis. Isn't that outside the parameters for A+ ? Shouldn't it have been assigned to a B reserve pilot?

I think they can change your Reserve Period if they give you enough notice ... I've received VCP (am launch) trips on B Reserve!*?

If they change your reserve period, they have to do it for the entire block, not just one day. Also, this pilot's reserve period doesn't show any change and it was assigned less than 18 hours prior which is how much notice they have to give.

Returning at 0045 has nothing to do with it being an A+ trip.
Did it launch during the A+ window?
Did it return on a base local day (until 0130) that you had reserve?

I was thinking of the requirement that a pilot had to be released to rest no later than 4 hours after the end of his RP. However upon rereading the section, it doesn't apply if a pilot is released for a legal rest period prior to the trip which is the case here. So it is legal. If he had not acknowledged the notification early he wouldn't be legal.

It's not unheard of, when they have nothing for a+ to do, for them to call the day before to release you for a trip the next day you'd be otherwise illegal for if you went on call at 6am.