some of them have long haul experience around the ITCZ and they all reckon than those CB ara avoidable as any CBs on the globe, moreover, the flight plan is studied together with the weather forcast before departure.
The effects of all CBs are avoidable if you take a long enough detour. The question is: Did they? Based on the impact flash that was seen in the satellite images the answer has to be no, they crashed under the CB outflow.
Also, based on my experience the forecasts in that are are next to useless - they either show CBs absolutely everywhere or in completely the wrong place.