IPv4 and IPv6 are two entirely autonomous protocols and don't interact in the same way that IPv4 does not interact with AppleTalk.
An IPv6 an IPv4 address can be configured on the same VLAN.
IPv6 and IPv4 protocols will not interact or affect each other even on the same broadcast domain because IPv6 uses multicast in ranges that IPv4 routers will drop.
It is not necessary to isolate IPv6 from IPv4 using VLANs but if you have an environment where clients are only running IPv6 then isolating those clients on a vlan will save CPU cycles on IPv4 clients by preventing them from processing and dropping the IPv6 multicast.
IPv6 should be blocked on any VLAN where it is not needed just like any other unnecessary protocol.
Routers will drop IPv6 packets received on an interface that does not have an IPv6 address configured.
Save CPU cycles by blocking IPv6 with a policy if it is not required to be switched and an ACL if IPv6 is required locally on the VLAN but is not to be routed.