This is not a new requirement. The majority of the immigration offices always ask proof of the TM30 report . Since nothing is ever 100% the same in Thailand some immigrations did not asked it on all.occasions. yours might just changed that recently as i understand.
All condo building can only be owned for 49% by foreigners. Its the foreign quota. If there is a unit for sale within the foreign quota you can 100% legally own it.