I believe Microsoft will eventually stop supporting .xls format, as Excel began using the .xlsx format with Excel 2007. It doesn't make sense to invest development dollars in legacy formats, so I wouldn't look for a native Microsoft .xls connector any time soon. That being said, there are many legacy systems still putting out the .xls format, and most of those do NOT support using Excel Tables as many OOB connectors require.
There are several commercial providers that have single step actions to convert; I have been using one of them for a couple years now to convert .xls to .csv with very good results. Some providers include Plumsail, Encodian, and Cloudmersive. Most of these you can find by just scrolling through the list of available actions when building your flow.