Unless the team is sponsored by Cervelo or another bonafide TT bike company-
The TT bike is more than likely NOT made by the company it is SUPPOSED to be made by. We all know that there is hardly any good TT bikes made by anyone else other than the BIG TT BIKE COMPANIES: Cervelo, Martec (who makes most of the carbon creations), some French company that is NOT Time or LOOK (MBK) or GIANT.
That’s an unfair generalization. I know that 13 of the companies with bikes in the tour make the TT frames that are being used in the tour. Most bike companies do contract manufacturing, including Cervelo, but that doesn’t really mean anything.
There are many many TT frames out there now that are very close to the P3 in terms of aerodynamics. Your wheel choice, aerobar choice, helmet choice, and whether you put on shoe covers or not is probably going to have more of an impact than your frame choice.
Yes, Cervelo does make a pretty damn good TT bike, and the P3 is the benchmark TT bike. But other companies have caught up since; you can only get so aero with a bike.
I dare say companies like Felt, Specialized, Trek, Pinarello, Orbea and Cannondale have pretty good bikes; you certainly can’t blame the bike for a poor TT performance.