Is there anyway I can change the datastore heatbeat to the new datastores?
Yes, you can change : Right click on cluster>>edit settings>><if HA is enabled, you will get option :"Datastore heartbeating"> >> Once you click on ":"Datastore heartbeating", you will get datastore ticked for heartbeating. >>Now you can un-tick the datastore that you want to unmount & select other new datastore which is listed there.