I am a longtime Anthrax fan who is new to this board. I liked the Joey era and the John era. Realistically I think that they are giving John time off to be with his baby. I don't think there would be any change if John didn't have a new baby. Anthrax needs a vocalist for touring so either they wait a year or more for him or they do the reunion. They left it open-ended because nobody really knows what the future will bring. John might want to quit the rock star life and focus on his family. I can say that I respect him highly for putting his baby first!
It does make sense why they would give the reunion a try. While their musical output from the Bush years is phenomenal, their sales aren't what they were. Some fans lost interest when Joey left. I am all for keeping John, but if it isn't working as good as it can they need to try and fix it. If having Joey and Danny back helps Anthrax to increase sales/popularity I am all for it. If it is one time thing, and if John is willing to actively tour, I am all for it. I guesss I must admit though that I am actually a Scott/Charlie/Frankie fan over an Anthrax fan. They could form a polka band and I would support it.
As far as the reunion, I am all for it. To me Anthrax has always been Charlie, Frankie, and Scott. As long at they are there I am happy. I like Rob, but I like Danny as well so I am happy to see Dan back. Rob has lots of other projects going on with Scrap 60 so it isn't like he isn't busy. I think that fans shouldn't ditch Anthrax over this.
On a side note I don't think it is possible to compare the two eras. There was such a shift in the sound that they are almost totally two separate bands to me. I loved all the Joey albums. They still hold up today as great examples of thrash metal. White Noise was lightyears beyond any metal record made by Metallica or Megadeth in the 90's.