2/10 追記
Security update available for Adobe Acrobat and Reader | APSB21-09 - Adobe Security Bulletin
追記終わり
21.001.20135 Planned update, Feb 09, 2021 - Release Notes for Acrobat DC Products
What's new in Acrobat DC
As Flash Player is no longer supported, the corresponding setting is removed from Acrobat preferences - Edit > 3D & Multimedia > Use Flash Player for playing 3D and multimedia content.