On the "Endpoint Security Homepage" sk117536 under "Client OS Support" you will see the following statement of Check Point:
If you check sk115192 as they are referring to, you will see that the GA of Windows 10 1903 has been released on 21/05/2019. Thus it will be a matter of weeks before the EA client will be available and a couple of months before the GA client will be available.
So it is not recommended (due to not being officially supported) to install Check Point Endpoint Agent E80.96 (or E81.00 - which is new from 22/05/2019).
But you can try and see if it works, but be careful... 🙂