Our support matrix is the definitive source for supported configurations. It does not mean other configurations will not work, just that they are not supported.
If you are using FC connectivity, it should work, but without our ability to perform troubleshooting beyond basic level. Other more significant challenges will apply if you're doing NFS, due to plugin compatibility for VAAI/VASA, as well as VSC for either FC or NFS.
I would consider the utility of remaining on Vmware 5.5, vs moving to 6.7, and looking at when you plan to replace or upgrade your storage controllers.