I think we'll still see RBs get in but they won't be comparable to what have traditionally thought. I ran a query using pro-football-reference's Player Season Finder. My criteria was a player had to have had a minimum of 1,000 rushing attempts and is in the Hall of Fame.
You can use their tool by following this link -
https://www.pro-football-reference.com/p...finder.cgi - and setting your search to Combined Seasons (section in yellow), Hall of Fame Yes, Position RB checked, and I added Additional Criteria Rushing Att 1000, Receptions 0, and Approx Value 1 (The last two so that I got stats returned).
Here's some assumptions:
1. I'm going to rule out the guys who played pre-1980 as possible matches.
2. I'm going to ignore Terrell Davis as he is an exception due to high massive career height.
3. I'm putting Curtis Martin as the cutoff point in terms of Approximate Value of 128.
4. I'm going as far back as 1989 for RBs. I figure with Davis waiting 17 years, it's unlikely anyone older than that gets in unless it's a veteran's committee pick.
With that, let's see what we have:
Lot's of guys I remember watching on TV, plenty of 10,000+ yard runners, but perhaps not tons of HoF candidates. I would think Edgerrin James makes it at some point along with Frank Gore. If no one has made any noise about Watters, Dunn, or Barber they probably won't. AP could make it in on the strength of his pure rushing stats and reputation. Ditto Marshawn Lynch.
Let's look at one more set of RBs. This time I dropped the attempts from 1,000 to 750 and only included active players:
Guys drafted before 2013 are probably too old at this point if they aren't towards the top of the list to be able to scrap enough together to make a HoF push. Even guys like CJ Anderson and Latavius Murray, useful players but are out of contention. That leaves us with these case studies to examine:
Le'Veon Bell, age 27, AV 60. He averages 12.5 AV a season but removing his mostly missed 2015 it's 13.75. Assuming he plays another 4 years at that level, he'd have an AV of 115. I think the missed year in his prime will ultimately sink his chances unless he can uncork multiple 2014 type seasons.
Todd Gurley, age 24, AV 47. He averages 11.75 AV a season though in a McVay offense he's averages 17.5. If he can give another 5 years at McVay levels, he'll wind up with 134 AV and a virtual lock.
Ezekiel Elliot, age 23, AV 39. He averages 13 AV a season and has led the league every year of his career in average yards per game. 2018 marked the first time he went over 2,000 yards combined offense. If he stays healthy and keeps up that pace another 6 years, he'll wind up with 117 AV but punch his way in on the AP route. Playing for the Cowboys certainly doesn't hurt either!
I think there could be a wellspring for Tiki Barber's candidacy at some point. It really is a shame he retired a year before the Giants won the Super Bowl in 2007 but at least he did play in the 2000 game. Similar to how Edge missed out on the Colts win in 2006.
Finally, obligatory homer analysis.
Matt Forte had a great career for the Bears but not hall worthy. Never had many chances in the playoffs though he did average 147 yards from scrimmage. 2 time Pro Bowl and once held the record for most catches by a RB in a single season. I'd sooner see Barber, Warrick Dunn, or Ricky Watters in first.
After his first two seasons Jordan Howard looked like a guy in the mold of Zeke Elliott or Adrian Peterson, a throwback to pounders. Now he's a complete after thought and rumors abound with him getting traded, though unlikely since he's on a cheap rookie deal still. He averages 1,100 yards per season on his career and if he could somehow keep that up for another 7 years through age 31 maybe he's in the conversation with an Eddie George type.