Is women allowed to remove their veils to fulfill something of lesser importance.

Question

Assalamooalaykoom,A month ago a mastoorat jamaat had been in our locality,Alhamdoolillah quite beneficial.Just one thing needs clarification,The mastoorat said in few days they were supposed to leave for Reunioun island,and they said they will be required not to wear their Veils,while entering Reunioun according to the country law,if they do not comply to it then they may be returned from the airport. And said see how we are sacrificing for The sake of deen,we will even remove our veils,you all must also sacrifice......Now my question is-Is it permissible to do or say such a thing? as I came across an article which mentions that women's going in deeni expedition is just a permissible act,and according to my knowledge women wearing a veil is an obligatory act which is mentioned in Holy Qooran.please enlighten us. Jazakoomoollah.