They will probably dry out and snap off. Once it is obvious which tips are dead a proper sharp pruning cut has to be 1% better. i can't imagine doing that for a grown tree though. Think of the time involved! i have a paperbark maple that suffers a bit every year. As much as I like it, I can't see that tree having a long life. Honestly same with this Acer palmatum purple ghost. We'll see if a more protected area helps it out. Otherwise I am going tontell them its a zone 7 tree lol. they look great in the botanical garden though 20 miles from my house. must be a different microclimate in the city lol.

It doesn't always happen, but as trees settle in to their new environment, they usually lose the tendency toward winter die back of branch tips. This sometimes takes as long as 5 years. In my own experience, this has been especially true of trees native to the Southeast such as oxydendrum and cercis. Common in most Japanese maples as well. Continued growth into the fall which gives the wood too little time to ripen before deep cold seems to be a major cause.

AFTER they leaf out ... you snip back to a proper pruning point.. just past a live bud ...

just to make it all look better ... on no tree/shrub/conifer ... do we leaves dead things ...

ken