I noticed that if I create a Wizard with Transmutation as his arcane tradition, and set the level to 10+ in order to have Shapechanger, then the Polymorph spell is not available for learning. Conversely, if I learn the spell before reaching the 10th level, I can keep it in my spellbook after reaching 10th. I guess that the correct behavior for Shapechanger is to allow one free use of Polymorph, rather than prevent additional uses as a regular spell.
I noticed that if I create a Wizard with Transmutation as his arcane tradition, and set the level to 10+ in order to have Shapechanger, then the Polymorph spell is not available for learning. Conversely, if I learn the spell before reaching the 10th level, I can keep it in my spellbook after reaching 10th. I guess that the correct behavior for Shapechanger is to allow one free use of Polymorph, rather than prevent additional uses as a regular spell.
Thank you for this report. I let the staff know.