A lot (all I can find) of the early tweets are about an Indonesian TV called Trans TV. This https://twitter.com/Safarazzz/status/208335499281182720 is (one of?) the first on topic tweet from 2012. After that it's a flood: https://twitter.com/patienceinbee/status/225368805285691393 https://twitter.com/noellejoyeuse/status/228993592864165888 and these were before Lana came out as trans. And then https://twitter.com/ontologicalgeek/status/25747720273043865... https://twitter.com/linernotesdanny/status/25764253274016153... and so forth and so forth.

So yeah, people have noted this for at least eight years, probably on other forums even longer.