Avalon Acoustics?

Manufacturers End of life drivers a lot of times. And speaker makers have no choice but to source new ones.  Are you talking about the C90-6-079 (vs the old 078) mid or the D20N6-31 tweeter?
if they use a 12dB per octave crossover I am certain they’d have to reverse the polarity and notate that the red dot.  

Call me a skeptic but I am hesitant to believe that the drivers are made to spec.  I do see wood spacers and ferrules which I can understand for mounting purposes.  They addressed the leaking goo syndrome that plagued the Eidolons and Ascendants appropriately I think.  

Samgar2 If your replacement mid is 1/4” higher then there would be trouble mounting into the cabinet. 
Note the black goo they use to get the back of the driver to mount flush against the supporting stud inside the cabinet.  If the new mid is indeed thicker it would spread the goo all over the place causing a mess.