That is a tough one to guess at, when? As other large cult following groups have now embraced in some limited form of digital streaming, I would think it is a matter of time. With APC and Puscifer now available, and with bigger artist names such as Pink Floyd, AC/DC which are still big draws at shows now on digital streaming, the clock is ticking for the group. I think the hang up is because the ownership of their music has changed hands several times due to label buy outs, so I would think that might be one of the big hold ups here.
I think we'll never have the ability to listen to their music through this app, or another digital and virtual app out there, you know, Tool is such an "live experience band", this means that they prefer you to buy the CD or vinyl (in order to appreciate the art in it beyonds just the music) and attend the concert by yourself (they don't even have an official live concert dvd on the market) because their performance is very complex, with lights, lasers, smoke, strobes, visual art and performance... besides that, is different to listen to them from your sofa than live because all the amount of live speakers that practically blow you away in a concert... (I have attended some lately)
Adan Jones is one of the principal member that won't allow any Tool stuff being digital out there, because besides he is the guitarrist, he is the band's artist... he made the sculptures and he is the production manager on the band's musical videos.
I agree with Jones, I'm a big Tool fan and believe me, they are so innovative, I'll recommend you to buy their original CD's or vinyls, they include innovative artwork on their stuff... and if you really like them I recommend you to attend some of his concerts, is just unbelievable...
Anyways, if you want some Tool-sound-like bands you can search for a superband named Soen on spotify, they sound similar, cheers bro, hope you like them