Yes, thin devices can be the source of a TF (vdev) snap and also the target of a snap restore. The only restriction is that a restore must be to the same type as the source. i.e. both must be either thick or thin.
I have couple of questions on TF Snap support for thin luns on VMAXe [VMAX10K] and VMAX      3.  For VMAX arrays, do we support TF Snap technology for thin source devices irrespective of Microcode version. That would mean                 that Vdevs could be used as target replica devices.  Since TF Clone VP Snap technology has come into picture since 5876 microcode version, we don't provide support for TF Snap for Thin Src on VMAX10K from 5876 onwards. Is this true for both VMAX and VMAX10K and whether the same applies to earlier Microcode versions?  Thanks.
TF Snap replication support for thin LUNs