I believe there is a misunderstanding on what the word deprecate means. This is not the same as the word remove. Deprecation states our intention to remove a feature, and that we will not add to or improve upon that feature.
If you take a look at any of the items on the deprecation tracker, we also include a removal point. Take this one for an example https://invisioncommunity.com/deprecation-tracker/commerce-ticket-system-r6/
If you take a look in the top right, it states here it will be removed in version 5. Therefore by definition, it will exist in 4. We will at some point stop support for it of course, as we will not support anything at all in version 4, but that is a long way away (current stated as 2025/2026)