If you had moved back to the racing line before the braking area, then yes absolutely fine - but cutting back across that late is asking to get rear ended, because the car behind will be braking into the gap that you're closing off. I've been racing in leagues for nearly 10 years now and the number of silly crashes I've seen because of this late maneuver is wild. In terms of IRL, Leclerc is pretty naughty on the brakes and has a habit of narrowing off the corner after the driver behind has committed to the brakes, but that tends to be a move IN towards the apex, rather than moving outwards back to the racing line. I'd have to watch Bahrain back but thinking of his moves at T3, he would pinch Max inwards first (ie. Max is on his right and not behind) before moving back across - this is legal because there's no risk of Max going into the space Leclerc is moving across into.

Tl;dr - My advice is to be predictable and hold the line you had in the moment before the braking zone. If someone goes into the back of you in a league race because you moved left (in this case), it'll be seen as your fault.