The guitarist was not part of the first leg of the reunited group's Not in This Lifetime Tour, and in a rare interview Axl admits he's not sure why.
"I don’t really know what to say about Izzy," Axl said. "It’s like you could have a conversation and think it's one way, and the next day it’s another way. And I'm not trying to take any shots at Izzy. It's just his thing is kind of his thing, whatever that is."
Frontman Rose, Slash and Duff MCKagan regrouped late last year (15) for a string of shows, which included a headlining spot at the Coachella music festival in California in April (16) and a summer stadium tour, which recently ended, and Izzy made it clear from the start he would not be part of the reunion.
In an email to Rolling Stone, he wrote: "At this point in time, I will not be playing at any of the April 2016 GNR shows... I've also not been in the studio recording or writing with any of the others recently. There is so much speculation, but so very little info, (that) I thought I should reach out."
He later added in a voicemail, "I wanted to clarify that I'm not in the studio recording with any of the GUNS N' ROSES guys. At this point in time, I'm not involved in the actual shows."
Stradlin co-founded the group with Axl Rose in 1985. He originally left in 1991 but has made occasional guest appearances.
Meanwhile, Axl has also spoken out about original drummer Steven Adler's role in the reunion, revealing health issues have prevented the rocker from joining the band of the road.
"When this started, Steven had just had back surgery and stuff," he revealed.
Adler has appeared briefly during select tour stops on the GNR tour.
Axl is now back on the road with his other supergroup AC DC, but the reunited classic Guns N' Roses line-up is plotting international dates for 2017 after the group's production manager, Dale Skjerseth, told reporters there's "no end date" for the band's ongoing tour, insisting Slash, Axl Rose and bassist Duff MCKagan are keen to "keep the machine going".