Is flv/f4v no longer supported my adobe? Looking for clarification on this

Hi,

Is the flv/f4v format no longer supported by Adobe?

I've been told by our designer that they are no longer able to export to flv/f4v from after effects or media encoder.

This link seems to be evident that this is indeed true...

removal of FLV and F4V export features from Adobe Media Encoder, After Effects, and Premiere Pro | After Effects regio…

I can make the necessary changes to the software in question to support mp4, however some of the content we use make use of keyframes a property that appears to be exclusive to the flv format.

I don't think this functionality is available in the mp4 format. If flv/f4v is indeed no long supported is their anything i can do to remedy this?

Thanks

Aidan