MMU is optional, unless you want virtual memory. The 68010 fixes a bug in the 68000 whereby it didn’t stack enough information to recover from an address or bus error, but you still need an MMU if you want to actually do virtual memory in any performant fashion.
My understanding was the 68010 had "support" for virtual memory when used with an MMU due to improved exception recovery handling. For example, when accessing an invalid / unmapped memory address. See https://en.wikipedia.org/wiki/Motorola_68010 68000's didn't have that capability. An MMU of some sort would still be needed to implement the virtual-to-physical mapping of memory addresses.
