Well, iOS 14 will only be formally announced by Apple in WWDC, which is in June. Apple hasn’t mentioned that release name anywhere yet. So any announcements you may have seen on device support would be speculations or rumors.

The existence of iOS 14 hasn’t been announced let alone device support.

Has not been announced. But the 6S/SE are the oldest devices supported by iOS 13, so I won't be surprised if they're dropped.

Keep in mind that the old SE was still being sold by Apple until just a year and a half ago (discontinued in Sep 2018). Generally, their devices can be expected to be supported for several years after they were newly purchased. I would be quite surprised if iOS 14 drops it, and have some hope for the release after that even.