The LG C9 has been available for over a year now. While the chipset doesn’t support HDMI 2.1 natively, it has a built in daughterchip to unlock full HDM 2.1 functionality. Incidentally it’s one of the most popular high-end TVs of last year (this years model is the CX). Since then many other TVs with full HDMI 2.1 functionality have been released and sold so no, not everyone will have to upgrade. ‘Next-gen ready’ TVs have been around for a while now.
Sony are very clever in marketing their upcoming TVs as PS5-ready. It seems that some people now think that this is cutting edge technology that isn’t available on the market yet.
Also most 120fps games will probably not be 4k so even HDMI 2.0, 120Hz TVs will be able to display some ‘true 120fps’ games.
