For some unknown reason (genetic weakness?), red barked Japanese maples like Japanese Sunrise, Sango Kaku, Beni Kawa, Fjellheim, etc. are overly prone to bacterial blight, Pseudomonas syringae.

Pseudomonas is a very common pathogen that affects a lot of different types of woody plants but can be particularly devastating with JM's. It is encouraged by winter cold damage and also wet and windy winter and spring conditions. It can also be spread by contaminated tools. Usually it just starts as a tip die back but can progress down into the more mature wood, leaving darkened, black discolored stems and branches in its wake. You can see that clearly on the branch to the right in the second photo.

Once it progresses into mature tissue, there's not a lot you can do. If caught early and just presented with the tip die back, you can prune out carefully beyond the sign of disease, sterilizing your pruners with each cut.

It is difficult to tell from just these two photos how much of a toehold the pathogen has but I do see some previous deadwood, that ominous blackened area and the weakened bark just above the graft and all of these are not encouraging signs. Is there any sign of bud formation on the branches?

I might wait just to see if anything happens a bit later in the season with the tree showing signs of life but I think I would be planning to replace it sooner rather than later. Sorry :-(