Here's the dollars and cents of the affair.
A few years back, Trains mag quoted a paint job on a new KCS locomotive at $27,000. That's for the stealth grey look, not the Belle look. It's safe to assume the Belle look costs more, as the complex paint jobs were the first thing to go in the 1960's when money got tight everywhere. Any road that went broke went solid-color first. (MILW, RI, PC, RDG, CNJ, D&H)
If the locomotive needs a paint job, spend the darn money - it keeps the rust out. If you want to celebrate a historic event coincidentally, go nuts and paint it in a fun look. If the locomotive doesn't need a paint job, wraps are available today at much lower cost. If you can legitimately calculate a positive ROI, it's an especially good idea, as that falls under the category of smart marketing.
Here's another anecdote once told by an MNCR crewman. Around the time the Gennies received their NH McGinnis look, one person commented to another that it was a famous paint scheme from the 1950's. The second person asked: "You mean they haven't painted this locomotive in fifty years?". Moral of the story? Save for the foamers and the design aficionados, nobody cares what color their locomotive is. They care that it carries them home to Naperville or New Rochelle on time every night.
Given that the purpose of a for-profit railroad is to increase shareholder wealth, and the job of a publicly-supported commuter line is to move maximum people safely, heritage paint schemes are neat but shouldn't be abused.
I am anxious to hear what Amtrak has up their sleeve, I would bet that the 8XX in PhIII needed a paint job if it's being overhauled.
The new Acela: It's not Aveliable.