My take:
The name "Prophet '08" probably made sense, and was arguably even clever at the time, because of the voice count and timing of release. And I'm sure it made sense in late 2007 because, who knew how this analog resurgence thing was going to go in the late 2000s when it was conceived? Problem is, the name doesn't scale well to the next revision, something I'm sure Dave was probably cringing over during the naming process for the Rev2.
So, the Prophet Rev2 dropped the year indicator (which is almost certainly a good idea), but made it sort of weird because there was a Prophet 5-Rev2 many decades back, and with voice count not being part of the name (it can't because there is a 8 and 16 voice version), it sort of comes across like the Prophet Rev 2 is *the* Prophet or flagship Prophet synth (when of course it is not).
This also creates a quandry for the Prophet 12, which did choose to include voice count in the name (but becomes a potential source of confusion when you release a Prophet 10 many years later, which is upmarket from the P12).
I'll just say, I don't have all the answers. I understand the challenges that went along with all this.... there's a saying among computer scientists that naming things is the hardest part (often sung in Tom Petty's voice), and I know marketing types like to think they have it all worked out, but after 40 years in technology product engineering, I'm say I'm REALLY glad Sequential is not a marketing-driven company, and it's one of the primary reasons they're still making great products.
In terms of naming Prophet 5 and Prophet 10, things seem to be on the right track to me here... I'm not sure these synths should ever see a "Rev 5", because reissuing vintage gear was their reason for existence.
For future product naming.. questions remain. What should the Prophet 12 successor be named? Maybe Propholver? Or Polyphet Digital Deluxe?
Prophet X line, from a sheer naming perspective, is in pretty good shape (could be Prophet X2, X3, etc).. It's just that the word is that Dave's samplers (however good I'm sure they are) do not appear the be the big seller for the company, so who knows where this will go.
Tempest2, 3, etc. (should they choose to go that route) I don't see a problem there.
Hopefully success of P5/10 leads to successful remakes of Oberheim units, just use the old name.
...One guy's opinion anyway.