Business is business. Friendship etc does not come in between for anyone.
and for anyone saying that Sallu will not clash with Zero because of friendship, that is not going to happen.
there can be only one reason for him to release Dabangg 3 after Christmas, which is that he believes Zero can damage D3's business.
remember, both Aditya and Sallu are some of SRK's closest friends, yet they planted Sultan against Raees.
SRK is very close to HR, and Rakesh is SRK's mentor, yet SRK clashed with Kaabil. But he preponed JHMS against TEPK, because either he believed that TEPK will damage JHMS, or that JHMS was not good enough.
Akki is also good friends with HR, but he still clashed Rustom with MD. however, he decided to move Padman away from Padmaavat.
even Karan is very close to SRK, and Rohit and Ranveer have a good equation with him, yet Simmba is coming 1 week after Zero.
so believing that someone will knowingly leave money on the table because of friendship is very naive. if D3 is completed in time for Christmas, then it will come on Christmas, unless Sallu believes that Zero can damage D3 or he thinks it is not good enough.