I don't mean a single night tournament like in the Pride days but something like boxing did with the super 6 tournament.
https://en.wikipedia.org/wiki/Super_Six_World_Boxing_Classic
IMO the MW title lost a bit of credibility lately since the top of the division is stacked with legit contenders and yet grandpa Hendo got the title shot and hardly anyone believes that Bisping is the best fighter in the division to begin with.
On the other hand I understand that because the division is so stacked it's hard to determine who the rightful contender is since they mostly have loses between each other while the undefeated Romero had that problem with suspension.
I think the best way to determine who the real top dog of the division is is to create a tournament, especially if Hendo somehow wins the title and then retires.
Personally I would put these 8 fighters in the tournament
Bisping
Weidman
Rockhold
Jacare
Yoel Romero
Mousasi
Anderson Silva
Whittaker
With Vitor and Uriah Hall as possible replacements in someone gets injured for a longer period of time.
I would put fighters in two groups of 4 with each of them fighting everyone in that group and the two with the best results would advance to the semi finals to meet the best two from the other group. Together that's 5 rounds of fights, it would be doable in 2-2.5 years.
The 2 groups could be determined by a random draw, but could be handpicked too to get the fights we haven't seen yet, in this case I would go with this:
Group 1: Jacare Weidman Bisping Whittaker
Group 2: Rockhold Romero Silva Mousasi
We would get plenty of great fights and a nice competition format that would produce clear contenders and finally also a clear undisputed champ. Whoever would come on top would be marketable as hell and would have a great resume. I think casuals would like this format too because it's similar to ball sports and is not based on subjective rankings.
In the meanwhile the rest of the division can fight each other to get the top contender out of the rest who would be the first defense of the new champ.
This tournament would be great for MMA as a sport, it would be absolutely stacked and would rival the legendary Pride tournaments.