Sanjay had joined Indigo in it’s earlier days in 2007 as Chief Commercial Officer and was currently the Chief Strategy and Revenue Officer. He is credited with creating Indigo’s mega spider web type of network.
In between in November 2018, Sanjay had left to join Air Asia as COO but returned back in December 2019.
He is now being replaced by Vinay Malhotra, who is currently the Head of Global Sales, and had recently joined from VFS.
Given the fact that post promoter settlement there have been some major management changes at Indigo, I would not be much concerned about Sanjay’s resignation.