no...this shouldn't be intentional, how could a mob take fall damage on their own 'land'? other fire resistent mobs such as zombified piglins just sink but never hit hard on lava. this should be fixed in future versions.
Can confirm in 21w06a. Just to inform you @unknown, the bug tracker is not a discussion forum. If you wish to discuss bugs, please do so on either the Mojira Reddit or Mojira Discord.
I added 21w07a to the list, and although some comments were saying things like it only applies to fall damages higher than 32 blocks, however I tested distances under 32 blocks (10 to 20 blocks) and the striders took damage, just like the 1.16.2 snapshots where I originally discovered this bug. The lava is deep enough, although I doubt depth has anything to do with it as they take damage (or die at high heights) immediately as they hit the lava. Unable to reproduce with mobs besides striders.
And whether this is intentional or not depends on Mojang Studios.
Happening for me in 1.16.2 pre-2 but not 1.16.1.