Great link (and I love Vimeo). The blog goes hyperbolic though: "In other words, if you happen to be in a part of the world where you might not have the best internet connection, AV1 will still provide you with an impeccable viewing experience."

No, AV1 is evolutionary. You'll "just" better quality for the same amount of bits (just like going from MPEG2 -> H.264 -> H.265 etc). The license of AV1 however is revolutionary.

Yes.

FFmpeg master is having for a while now, if you could grab latest nightly, you can use it. https://ffmpeg.org/ffmpeg-codecs.html#librav1e