That is unfortunate. Though, they seem dedicated to follow up on this half year promise so I’m optimistic.
Therefore, depending on how you feel about half a year of not having the latest security updates, you can pivot. I’d say for anyone with a mid to high threat model should definitely consider migrating and low threat model people are probably fine to make their own choices.
I’ll personally be considering it a bit to migrate to a different custom ROM for the coming half year, though not sure yet if I truly need to. This graph is really useful for comparing popular custom ROMs, so anyone reading this, do check it out.