The datasheets contain statements like
...the AD72x requires interlaced RGB video and clock rates that are consistent with those required by the television standards.
...the RGB output scanning must be interlaced and at the proper scanning frequencies for either NTSC or PAL operation.
This is also mentioned in this discussion:
But it is not clear whether these statements in the datasheets are unconditional statements or whether they apply only for the case when connecting to a TV.