I think Fanta is mostly working chronologically, though without the mania for completism that their massive Peanuts project had. They've published...I don't know, five or six? maybe more? books of Bushmiller, starting (I think) with Nancy Is Happy about a decade ago. That book had war-time strips, and the books since, as far as I can tell, each collect roughly two years of dailies.
So Nancy Wears Hats, which was published earlier this summer, collects many - it doesn't seem to be all; the description says "over 300" - strips from 1949-50.
Let me digress for the potted history lesson. The strip Fritzi Ritz, one of many jumping on the flapper bandwagon (Blondie is the only thing left standing in that field), was started in 1922 by Larry Whittington. A twenty-year-old Bushmiller took it over three years later and did mostly flapperesque gags for the next decade, but then invented a niece for Fritzi in 1933. Nancy gradually took over the Fritzi Ritz strip, as Bushmiller gradually added different supporting characters and dropped the showgirl and office gags associated with Fritzi, with the strip finally changing names in 1938. Bushmiller wrote and drew Nancy until his death in 1982; it was continued by other hands since then and is still running, recently rejuvenated by the pseudonymous Olivia Jaimes. Bushmiller is beloved in comics circles for his simplicity: he drew cleanly and made precise gags that famously are easier to read than not to. His best period is generally considered to be the '50s, but it seems more to be that he took a few years first to turn Fritzi into Nancy, and then to tune Nancy to his preferred pure-gag level. I don't think there's a generally-recognized decline at the end of his run.
So: this book is full of fun Bushmiller gags, from the beginning of his best period. If you've been reading the Bushmiller reruns on GoComics - and why wouldn't you? - it might be a bit of déjà vu, since they're right in the middle of this period right now. (I guess that means everyone agrees this is peak Bushmiller.)
There are a few short "continuities" here - a week or maybe two of gags on the same theme or starting from the same premise - but Nancy was never a continuity strip. It was about the gags, and there's a flood of fun gags here: some timeless, some very 1949. I like the latter, since they're often still funny, in their own way, and I find that kind of thing fascinating - your mileage may vary.
I think Bushmiller got his drawing a bit simpler than this in the immediately subsequent years; there's some places where his drawing is more detailed - not fussy, but more lines, drawing things that later Bushmiller probably would simplify to make the gag sharper - than at his very peak. But this is a big batch of fine funny strips from a master.