Well "at this stage" itself Jai Ho, PRDP, Tubelight & Race 3 happened.
First of all Arbaaz was also the producer of Dabangg 1 too. For a commercial film of Dabangg template, it is foolish to make it a 100cr budget film. The heart of Dabangg lies in it's simplicity & raw desi-ness.
And nowhere story has been revealed. Do you really think it'll be a prequel just because Salman for fun spilled it many years ago?
Another 3-4 years means Salman will be 57. Are you sure at that time he will be still "allowed" to make a Dabangg? It is Bollywood not Tollywood for any of the Khans to play Rajinikanth or Balakrishna from South. Don't expect such support ever from Bollywood audience or fans.
Any good run has to stop. For almost entire decade, Srk struggled to find what actually his audienc want. And he struggled. Till 2017 Salman didn't go through that dilemma & then Tubelight happened. A movie he made with utmost conviction was rejected. A movie he basically sleepwalked for most part of the film became his highest grosser, TZH. Race 3 is solely the result of TZH. Now he's taking one last risk with Bharat, hoping for a turn around.
People mocked Srk all over this decade. Imagine the plight of Salman Khan if his attempts at non-action films are rejected & the his own fans say no to his "action" films especially Dabangg which started his unmatched Blockbuster run this decade.
And yes one can argue how well received / appreciated TZH was. But the fact remains, he just showed up at the shooting venue & went with the emotions casually. His films where he actually dedicated himself as an actor this decade will not include Ready, Ek Tha Tiger, Tiger Zinda Hai & Race 3. Infact he was involved in Ready & every single thing which worked there, he repeated in Race 3. Only thing is Race 3 backfired terribly. You can check the similarities. He basically made sure whatever he said was final, he ordered reshots & demanded what all to be included. Worked well in Ready (both Character dheela & Dhinka Chika were re-shot, cameos of Sanju-Ajay-Kangana were included. Yes the original had cameos but here it was Salman's call on whom all will be part of it. Plus all the changed dialogues.) And he did all of it again for Race 3 & you know what happened.