No, this does not seem to be the case. Same circumstances, upgraded from 1.2 > 1.5 and it immediately said "the license is not valid for this version". I manualy put in the key from my e-mail. Same thing. AIDA will not even start.
UPDATE: Went to the upgrade page mentioned in the sticky. Re-entered my Everest key and was given a new AIDA64 key that does work. Possibly a glitch with FinalWire's database? Anyways. No harm, no foul. But it is lucky I still had my Everest confirmation e-mail saved.