First of all, let me say that this bird looks beautiful. Almost like a sleek F-16 cousin, lol.
Now coming on to your question. Well, we already have integrated SAAW in Hawk-i. So we are looking for CAS/ground attack duty from it. Hence, it's obvious that HLFT-42 would be used for that role too. It's going to be much more effective than Hawk(s) in that role being bigger and faster.
Plus, we can target international markets with this as a cheap light-weight fighter. Tejas is expensive because of composite use, HLFT-42 is going to be a full metal bird, so much more cheaper for training/CAS/Ground-Attack roles as a light fighter/supersonic trainer.
Man, it warms my heart to see India indigenously design such good looking planes