Peter Porker is a frozen character. Disney/Marvel had to give Sony the OK to use him in Spider Verse
2.b(i)(A) Spider-Man Character. The character “Spider-Man,” including without limitation the character “Peter Parker” and all Alternate Versions of the Spider-Man Character, and all other versions, iterations and alter egos of such character appearing in any Existing Authorized Work or New Authorized Work (other than solely in an Incidental Depiction) (collectively the “Spider-Man Character“). For the avoidance of doubt, neither SPE nor Marvel may exercise the Rights to the Frozen Characters listed on Schedule 7A (e.g., “Spider-Ham”).
2.g. Frozen Characters. The characters listed on Schedule 7A (“Frozen Characters“) are frozen and any and all exploitation of the Rights to such Frozen Characters is subject to the mutual consent of the parties.
4.e. Frozen Characters. During the Production Term, all Rights in and to the Frozen Characters listed on Schedule 7A (e.g., “Spider-Ham”) are frozen and may not be exploited at any time by either SPE or Marvel without the written consent of the other Party.
And yes, Spider Ham/Peter Porker is listed in schedule 7A Frozen characters.
Kingpin is a shared character and can freely be used by either party with some small restrictions (i.e. have to notify the other party). So that wasn't a stoppage. Peter Porker is a big question mark and makes me wonder what Disney/Marvel got in exchange for it (probably just money).