It's a moulding thing. Just how the mould is built and how the plastic they used mixes in it I guess.
I don't think there's anything to worry about. It's not cracking or anything. Like this release has been plagued by genuine toy- breaking QC issues. No use sweating over a curious result of moulding techniques that doesn't seem to be structurally compromised.
mix. This has also always worried me because really, how is gray/silver plastic different from mustard/gold plastic in a way that makes the former impervious to or less susceptible to the shattering of the latter?
The answer is it doesn't! But you still shouldn't be worried.
GPS is really unfortunately named because it wasn't specifically gold plastic that was affected, but just plastic with metallic flakes in general. GPS has cropped up across toylines with multiple colours, because metallic flaked plastic was one of the 90s' big things.
The issue, as best as I understand it, is that the metallic flakes added to the plastic keep the plastic molecules from properly bonding. The colour of the flakes and plastic doesn't affect anything, it's the faulty mixing process.
It's the mixing process that's important. Take G1 Thunderclash, famous GPS sufferer. I got myself a complete one a bit ago and after a few tenuous transformations realized he wasn't shattering, even after all this time.
So I looked into it.
Basically Thunderclash had two production runs. The first had gold plastic that used a high amount of flakes to bring out the shiny gold colour. This is the run of figures that crumbles into sadness.
The second run reduced the amount of gold flakes in the gold plastic, leaving the gold bits a bit of a darker caramel. Mine is from this second run, and by all accounts the reduced gold flake usage in the plastic has left it far more durable over the decades.
I'm still not going to make a habit of transforming the thing, but I have put him into base mode, including putting stress on some gold plastic load bearing pieces, and it's still holding together.
All of this is to say that the real culprit of GPS isn't the gold colour, but faulty processes in how metallic flakes mixed with plastic in the 90s. Silver was just as susceptible.
The good news here is that Hasbro fixed the issue with their metallic plastic mixtures on their end a while ago (Takara admittedly took longer) and has been rolling out plastic with metallic flakes in it for decades now without issue.