This is still the same behaviour in 2022 on Windows. When a user no longer has Acrobat Pro/Standard licence, Acrobat Pro/Standard shows a 'buy license now' or 'sign in' prompt. Closing either prompt would exit the Acrobat program with no further explanation.
Creative Cloud Desktop App can also aggravate the issue. For example, on a machine pre-installed with Adobe Reader DC only, and a user with an Acrobat Pro/Standard license logs in to the CC Desktop App, the CC App would auto-upgrade Reader DC to Pro/Standard DC, but the other way is not true. It would not downgrade to Reader when a user signs out or loses license.
The auto-upgrade feature would be beneficial if, Acrobat behaves in a read-only mode with no active license. Also, auto-upgrade is not consistent, so sometimes, users with an Acrobat license would be stuck on Reader DC, while the CC Desktop app reports the Acrobat DC is installed and up-to-date. If Acrobat DC can behave as read-only mode, then we don't have to bother installing Reader DC and Acrobat DC side-by-side and deal with switching Default Apps between the two.
This is still the same behaviour in 2022 on Windows. When a user no longer has Acrobat Pro/Standard licence, Acrobat Pro/Standard shows a 'buy license now' or 'sign in' prompt. Closing either prompt would exit the Acrobat program with no further explanation.
Creative Cloud Desktop App can also aggravate the issue. For example, on a machine pre-installed with Adobe Reader DC only, and a user with an Acrobat Pro/Standard license logs in to the CC Desktop App, the CC App would auto-upgrade Reader DC to Pro/Standard DC, but the other way is not true. It would not downgrade to Reader when a user signs out or loses license.
The auto-upgrade feature would be beneficial if, Acrobat behaves in a read-only mode with no active license. Also, auto-upgrade is not consistent, so sometimes, users with an Acrobat license would be stuck on Reader DC, while the CC Desktop app reports the Acrobat DC is installed and up-to-date. If Acrobat DC can behave as read-only mode, then we don't have to bother installing Reader DC and Acrobat DC side-by-side and deal with switching Default Apps between the two.