...inaccurate.
The reason why the early Hasbro BW bios are different from the cartoon is because they were written before the cartoon came out, and at that time Hasbro (well, Kenner) intended for BW to be a continuation of G1/G2. It wasn't until _after_ Mainframe was commissioned to make the cartoon that the creators decided to change the story to what we are more familiar with today (e.g. establishing Optimus Primal as a separate character).
Takara on the other hand released Beast Wars a year later... by this time the cartoon had already been produced and Takara had the advantage of being able to make their BW toy line fit the cartoon. This is why:
+ Even Takara's early BW toy package/tech specs art is more show-like and less toy-accurate. They also had screen caps of their beast modes.
e.g.: Convoy (note the "mouth" on the robot art), Tigatron etc.
+ Every early Takara BW toy package had a sticker advertising the cartoon as "world's first 100% CG transforming robot animation"
+ Some toys featured a more show-like colour scheme, e.g. Blackarachnia, Tigatron etc.
+ The tech specs for Convoy (Optimus Primal) and Megatron don't make any allusions to them being their G1 namesakes (unlike Hasbro's)
+ The tech specs for Convobat and Megalligator DO explicitly state that they are G1 Convoy & Megatron.
+ The first JP BW catalogue has screen caps from the cartoon
+ Convobat & Megalligator both came packaged with an exclusive CD-ROM which shows clips from the cartoon
So whereas Hasbro's early BW came out _before_ the cartoon, Takara's BW started _after_ the cartoon... so trying to compare them like that is like apples and oranges...
Well, it started long before him. Remember in G1 Transformers were already downsizing themselves as Micromasters to conserve Energon. The Maximal Upgrade was the next phase.
Another reason why it was done from a story telling POV is because the BW writers wanted to make the G1 Transformers look like godlike titans compared to BW Transformers. Also a Freightliner semi-truck would be way huger than a silverback gorilla.
As I said back in post #6, Convobat's tech specs says that he is G1 Optimus Prime (and likewise Megalligator's tech specs states that he's Megatron).
The first sentence of Convobat's tech specs states:
"コンボイ司令官といえば、一般的にトレーラートラックが有名。"
Which means, "Commander Optimus Prime is generally known for being a semi-truck. (the rest of the tech specs bio talks about how he's now a bat) -- likewise Megalligator's tech specs also starts off saying that he was once a Walther P-38 gun but now he's a croc/alligator (the Japanese word ワニ refers to any kind of crocodilia and doesn't specify if it's a croc, gator, caiman etc.)
I don't see why not. When it comes to Optimuses and reformatting their bodies... well, remember when Optimus Primal became Optimal Optimus, and Cheetor says, "Wow, Optimus sure gets used to a new body fast!" -- Rattrap replies, "Eh whaddaya expect, he changes them often enough!" <rimshot>
Throughout G1 Optimus Prime underwent changes to his body such as (yes, I know I'm blending different continuities here too - BW follows on from a blended G1 continuity anyway):
+ Orion Pax -> Optimus Prime (Cybertronian)
+ 1st Cybertronian mode to 2nd Cybertronian mode
+ 2nd Cybertronian mode to Earth mode (1st)
+ change to Powermaster
+ change to Action Master
+ change to Star Convoy (w/ Micromaster Hot Rod!)
+ change to 1st G2
+ change to Hero
+ change to Laser Rod
+ change to Go-Bot
+ change to Machine Wars
...etc.
So I don't think it's that much of a stretch for him to then change to Convobat after that IMO.