No, it's not clear what happened from just the transfer speeds.

It becomes clear when you see that first party cables that enable hight transfer speeds are sold at 79, 149, and 179 bucks for the 1m, 1.8m, and 3m respectively [1]. So, in essence, they purposely did just enough to comply with EU regulations while still aiming at milking customers' wallets with crazy expensive accessories that you would take for granted from top or premium tier smartphones.

[1] https://www.apple.com/ie/shop/product/MU883ZM/A/thunderbolt-...