A couple of data points.
LHR-HEL in mid-June on A330 has been waitlisted a week now
CPH-HEL the week after was waitlisted a day, then cleared
These were for only me (plat).
The MIA-HEL flights in mid-December still waitlisted (2 spouse upgrades, one with my voucher), has been so for some months now. The HEL-MIA segments cleared a few weeks ago. I’ve posted about these earlier.