As I understand the state laws - not if it's not stated as such. They don't allow it to be implicit in "you get salary X each year and operate under noncompete

As I understand the state laws - not if it's not stated as such. They don't allow it to be implicit in "you get salary X each year and operate under noncompete Y". A restriction on future work like that would require explicit compensation. (And as for why people don't just add "compensated via your salary" to the boilerplate - that's an open-ended transaction, not a defined amount of compensation for the year of noncompete restriction.)