Transformers are, and have always been, 'borne of Cybertron' as Autobots and Decepticons (and Maximals & Predacons in BW), as in given life through Cybertronian means, not through Human or alien bonding. Humans using robot bodies may have joined the Autobot & Decepticon causes, but they weren't born as Autobots & Decepticons. Same with the Godmasters - they don't appear to be of the Transformers Race, as they seem to be some other type of lifeform/race that is effectively gatecrashing the Autobot/Decepticon war.
So far the only pure (Cybertronian) Transformers in this series are the Pretenders and Seacons. And we don't get to see much of either now.
Ep 9 - A Fierce Battle!! The Autobots Are in Trouble
Under the new leadership of Giga and Mega, the Decepticons start to renew their conquest of earth by attacking an energy facility. The Decepticon Pretenders resent being forced to make way for the new recruits. Despite being outmatched, the Autobots still manage to fight off the Decepticons.
Seems that the Godmasters have a lot of special powers, and should be able to easily defeat the Autobots, but still don't manage it.
And one of those special powers appears to be regeneration when they get damaged.
It doesn't surprise me to have the Decepticon Pretenders, the real Decepticons, not liking being treated as inferior to all these people and humans now joining the Decepticons. After all, those three are real sentient robots from the race of Decepticons... all the rest are merely Decepticon wannabees.
Ep 10 - A Hero Is Chosen - His Name Is Ginrai
Buster and Hydra are sent out by Giga and Mega to search for other Godmasters, but Diver finds one first. Or at least, finds a human who has already bonded with one, but doesn't know it until he touches his two bracelets together.
So after a couple episodes with Godmasters, we're kinda told what they really are. It seems that Giga and Mega are some sort of strange lifeform, and their offspring have disappeared around the Earth. And they have the ability to inhabit vehicles (or become them), waiting for a compatible human to then bond with, through special bracelets. Which coincidentally are similar to the Headmaster Bracelets that the off-world Autobots created. Plus, for some reason the offspring don't know who or what they are, so will align themselves to Autobots if they end up bonding with someone who is against the Decepticons.
What this means, the Godmaster Transtectors are actually alive, and the purpose of the human partner is only to combine the 3 energies that the Decepticons mentioned earlier in the series.
The regenerating of the truck bumper wasn't shown, and the damage was even significant enough to be something others would have noticed regenerating. So I don't see how the Decepticons would have heard about a 'rumour of a regenerating truck' within hours of it happening.
It'll be interesting to see if they try to explain why a Decepticon offspring looks so much like Convoy (Optimus Prime). The explanation given so far doesn't say why it would choose that particular truck and robot form.