Are all new tv's Air Play compatible ?

No. Look at the specs for it.

For any others that stumble across this thread, every TV manufacturer has different lines of TVs that add features, so one Samsung/LG is not necessarily equal to the next.

Just for the QLED tvs from Samsung, there are the Q60, Q70, Q80, and Q90. Outside of QLED4k, there is another series of lines for QLED8K, Neo QLED, OLED, Crystal UHD, and Lifestyle TVs, all with different submodels that may or may not have features like Airplay, Bluetooth, etc. And that's just for Samsung this season.