Oh, you missed the part where Frenchie asked the same question about the new engine for F-35.Rafale is not underpowered. Hell, the IAF doesn't consider the M2000 to be underpowered, and the Rafale beats the M2000 by a very wide margin. Rafale pilots speak of how they have to throttle down in order to not overshoot the M2000 during dog fights. Plus it can supercruise, can't do that without adequate thrust.
Anyway, all engines have the potential to undergo a 5-10% thrust upgrade through modifications to the existing engine, which is meant to cater to the jet's growth by the time it hits MLUs. Meaning an engine upgrade that's expected to happen during MLU is a scheduled upgrade. Deliverance here wants to create false equivalence with the F-35, which doesn't just need an engine upgrade but a whole new engine with a 30% boost in thrust just to be relevant.
Companies also like to push for engine upgrades because they can make more money. Engine upgrades happen when the airframe OEM or the air force ask for it, not when the engine OEM demands it. Which is why the article also says: "However, the upgrade issue had not been discussed with Dassault Aviation, the Safran CEO added." Only time will tell whether the F4 will come with an uprated engine. But that's only a natural evolution of the jet.
If Dassault meets IN's carrier requirements with the same engine next year, then the AF version doesn't need a thrust upgrade.
Anyway, UAE definitely asked for high thrust so there you have it.