No, it is not up to date.
The original book and its update were both very much in favor of deep stops during a decompression dive ascent. The technical diving community as a whole has moved away from that.
Here is an article I wrote a few years ago on the topic, and I note in it that Powell had changed his thinking. You can read Powell's change in thinking from about 6 years ago
here.
Here is part of his conclusion:
OVERALL WE CAN DRAW a number of conclusions from recent studies and discussions. The first is that “deep stops” is a misleading term that doesn’t always help the discussion.
Perhaps it’s time to move away from using this term in favour of being more specific as to exactly what sort of stops we’re talking about.
The next conclusion is that it is definitely possible to stop too deep, as shown by some of the examples above. Some of the advice given over the past few years has clearly been introducing stops that are too deep.
What he says there is pretty much what most researchers think today. The stops recommended by the pure Buhlmann algorithm are probably not deep enough, but the deep stops recommended by VPM, RGBM, and others (including Powell's book) 15 years ago are too deep.
