As part of the refactoring in T330872, the core message blockedtext-reason-comment became reused in several other messages, such as blockedtext-tempuser in core and globalblocking-blockedtext-ip in the GlobalBlocking extension.

Some of those messages, such as globalblocking-blockedtext-ip, became completely composed of other messages, which means that translating them to most languages is no longer needed (in translatewiki terms, they are optional).

One of the few cases where such translation would be needed is Bengali, where the full stop was replaced in the composed messages with Danda, a character that is used similarly to a full stop in many languages of South Asia.

A better solution would be to add the full stop into the blockedtext-reason-comment, making the sentence complete, and to remove the full stop from the composed message. This would make the "translation" into Bengali and other South Asian languages unnecessary, too. This would also be consistent with the conventions in https://www.mediawiki.org/wiki/Help:System_message about punctuation in general and full stops in particular.