I asked a few questions and the official, who we've know 7 years and usually seems to give accurate info, said the following:
1) Applies to all property where land registered to wife after marriage, ie: even where no 'declaration that funds are all Thais' sign-off was done.
2) If wife says husband back in home country/ran off with pool cleaning boy/can't locate him then land office needs a court doc or similar.
3) If wife says we're divorced now needs a divorce cert/court paper.
4) Said this was a regulation all the time but never really enforced all the time by all officials or all land offices. Maybe if husband there anyway they would get him sign.
This reinforces the cases where something's gone wrong and a judge has generally ruled for a 50/50 split in the usual instance where the funds were payed 100% by farang, but the ownership was registered 100% with the Thai. Apparently under the CCC laws a judge can not accept the land office 'declaration that funds are all Thais' sign-off form. I've read they can adjudge differently to 50/50 where there's more involved, adultery, violence, abuse etc.
Seems the authorities have got tired of upstart wives selling up behind a husband's back, the bad publicity it brings, or just purely that it wastes police/court's time & money (latter added for the bitters to cling to). Whatever the reason though it's a positive move on several fronts.

SJ