Hello,
This looks like damage from the freezes we had in early May. Monitor the plant and if you see more blackening on mature leaves that are green right now,  please write me again. Some buds may have been damaged by freezing so, new sprouting leaves can show damaged edges as they grow.

The best time to move a shrub is when it is dormant in the spring. The second best time is in early fall. Both of these times avoid the hot summer weather that a loss of roots would aggravate. However, viburnums are easily transplanted. If you are willing to give extra care over the summer, you may be successful moving it now. Key points are- dig a properly sized root ball, plant at the correct depth( not too deep), mulch the root zone but don’t pile mulch against the trunks, keep it watered but not drowning.

Here are some guides on the steps to follow, root ball size to dig and care-