I don't expect the Mk2 to be produced anytime before 2027.
HAL is hoping the IAF will add 3 more squadrons to the Mk1A's order. Another goal is exports. If IAF refuses, HAL wants to sell the excess production to countries like Malaysia or Vietnam. A bunch of countries have shown interest in the jet.
2027 is too much. If 2027 is the time, we should go with AMCA. IAF accepted Mk2 only cos it was told it has little design modifications and same components will used in Mk1a will be used in Mk2, except extension of fuselage and new engine. It will mean testing time should be kept within 2-3 years. Plan is to make just 2 prototypes.