using the new query.health query in 1.16, it does not accurately report the health value of the entity if he or she has absorption. 

how to reproduce: 
1) download the sample pack I have attached and apply it to a new world
2) give yourself the absorption effect, with any amplifier

3)  take damage, either by taking fall damage, shooting yourself with an arrow, etc. anything works

4) compare this to taking damage without the absorption effect, without the effect it works just fine

You will notice that the health value displayed from the /tellraw doesn't change even though you are losing hearts that were originally gained by the absorption effect (I have a /tellraw command displaying the health to play whenever the health of the player changes). I have these commands set up for up to 36 health (18 hearts). Also, I applied these commands to run if a player takes damage, as thats how I have it set up.

I think it would be extremely useful to have a query such as query.absorption and we can add the values of query.absorption + query.health to get the real health with status effects

Below I attached an example pack for you to test this.