Yes, these older templates and workflows are now not installed by default. If you think about this, we have near what, 20+ years of templates? Visual Studio is simply an amazing tool, but it also has oh so many features, that now by default, not all of the workflows for say webforms is installed by default.
However, they are all still available.
Tools->get tools and features.
You want to check/install these workflows:
I would check all the ones I have in above, but the "Additional project templates (Previous versions)" I point out in above is the most critical one you require. However, I would check most of what I have above.