Can tardigrades survive being eaten?
In there natural state no, tartigrade have absolutely no way to survive the acidic content of stomachs and are fragile. 

In their cryptobiosed form (extremely resilient form) there has been no research to determine if they could survive extremely acid environnements. The things that we know they can survive is: 


Temperature
Pressure
Dehydration
Radiation
The outer space environnement
Toxins


However, very few organisms possess mechanisms to tolerate highly acid environnement since acid affect cell membranes by "attacking" mainly the proteins and lipids. These organisms have evolved these traits because they live in acidic environnements, tartigrades on the other side don't. 

Another point to add is, entering cryptobiosed form takes time, if the tartigrade would be eaten in it's natural form, it wouldn't have the time to cryptobiose and thus it would die.  

Tartigrades

I hope this gives you some useful information