What do you mean by cloud will determine what is possible and what is not .
If you're looking for SAP Cloud solution then no Xi3.1 is not available there, only BI4.1 is available in SAP Cloud.
If you want to develop your own cloud solution - then sure, why not.
cloud is simply a fancy name for a client -server distributed solution available 24x7.
It will cost a lot and will be hard to implement, but anything is possible.