I do not think Cypher ultimate right now is necessarily weak. It can still help out a lot during a match. The thing is, it is underwhelming. Even though his ultimate is cheaper compared to other sentinels, it doesn't have nearly as much value compared to them. I have a few ideas to get it balanced, though they are similar to some stuff already proposed.

1- Remove the range limit of his ultimate. That's the least they could do. It already requires a dead enemy in your line of sight, adding a range requirement on top of it is just too much.

2- Tag people instead of just snapshoting them. Just like what the camera does, tagging people and requiring them to take out an "arrow" could be a decent buff without changing the ability too much. It would delay a push even if just a little, and actually give teammates enough time to react properly.

3- Pinging people three times, just like Sova's arrow. Of course, this is a pretty strong buff. So as a counter part the cost of the ultimate could be increased. Alternatively, there could be a delay for the hat to reveal enemy locations but making the hat destroyable in the process, like Killjoy's ultimate.

4- Extra debuff. Applying a deafen/concuss/nearsight effect after revealing enemy locations once again would be a decent buff. The cost of the ultimate could be increased depending on how strong the said debuff is.

5- Rework. I don't need to explain this much, having the ability completely changed would also work depending on the new ability.