>https://federalnewsnetwork.com/government-shutdown/2019/01/furloughed-feds-wont-be-rifed-if-government-shutdown-extends-past-30-days-omb-says/
First sentence:
Agencies won’t need to consider targeted layoffs, otherwise known as reductions-in-force (RIFs),
Won't need to consider = not mandatory =/= can not
Rest of article indicates RIFs might be possible because regulation (Title 5) applies to cases of known duration factors, not those of unknown duration. IOW they don't apply here. OPM also not sure about sending furlough time notices or not.
Looks like they don't know for sure. Never happened before.
Could it be why Pelosi (who found out by reading the newspaper yesterday?) sends POTUS a letter today saying open up by Friday or no SOTU, giving a sham security excuse as the reason.