TMZ Hip Hop has learned Krayzie, Layzie, Bizzy, Wish and Flesh are reuniting for Bobby Dee and Snoop Dogg's "High Hopes Concert" series … which is loaded with hip hop legends.

Following the concert series, the group will still tour as a quartet minus Bizzy's involvement ... making this particular tour a must-see for hip hop fans.

Ice Cube, Method Man & Redman, Warren G, Xzibit, Cypress Hill and Tha Dogg Pound will all be in the mix -- and we're told this will certainly be the last ride for the Bone Thugs boys as a full group.

Bone Thugs' affairs have been wobbly for decades, with various members rotating in and out of the touring lineup but Bizzy's rep August Keen assures us everyone is on board to reunite time around.

Bizzy stands as the biggest deflector and he recently called out the other 4 members on a tune called "Bizzy Get's Busy," where he spits ... "Why the f*** is Bone Thugs doing a show without Bizzy?/ I'll say it again, you should be able to say what you want if they really your friends!!!"

Krayzie wondered the same thing when the group hit the road following their Verzuz battle with Three 6 Mafia -- which turned into a boxing battle when Bizzy and Juicy J squared off on stage -- but all appears to be good in the hood, for now.