It may not be going to go away, but is it going anyplace either. The last twice, the Nats, the main and loudest proponents for Indie have only been able to legitimately claim an overall majority by selling out and getting in bed with the Greens. Hardly a resounding endorsement of their flagship policy.
Dissention for the union/indie has always existed as long as the union has been in existence, just not enough to force it's dissolution, and that doesn't seem to be growing of declining with time. The only change has been a bunch of wannabe central belt socialist who've hijacked it as a potential easy ride to personal glory and blaring about it from a bullhorn these last two or three decades.