Sounds true. When in FEB I had a 5 hour delay for my MIA-CPH flight and showed up at the airport 2 hours before (scheduled) departure time, I requested to be rebooked to LH (flights to FRA and MUC departed in the early evening whereas the revised departure time of SAS was 1AM) which the check-in staff declined as not possible (didn't appear to be SAS staff except for a supervisor looking guy)). One senior agent even called someone (I don't know who/where he called) and apparently was told "no rebooking".

Well, SAS ended up paying EUR 600 for the delay so it may have been cheaper just to rebook.