Well, seems like there is some confusion. Some news sources phrased it as "T2 will have only international flights after August" while others phrased it as "Only T2 will have international flights after August". The latter makes more sense and is kind of like the arrangement at Mumbai now, where the newer, "better" terminal is used for all international flights + the premium domestic airlines, while the older terminal is relegated for use by the low-cost domestic airlines.

However, even in this there is a further twist now:
https://www.newindianexpress.com/cit...r-2610089.html

Edit: If you don't want to follow the link, the summary is that they've announced the transition of international flights to T2 is indefinitely postponed.