Hopefully the "appropriate time" is a bit less last minute than most of the legislation/regulations that have been put in place but we can only wait and see i guess !
( Also this "holiday" actually isn't to a destination that would be covered by any "International Travel Ban" I imagine so not that sure what the case would be in late April .. regardless I imagine I'll be rescheduling it anyway and this suits me to have the option without hanging around for the inevitable cancellation )
Anyways, to the original point SMS only communication seemed a bit unusual from BA also the link in the SMS wasn't a BA.com URL which looked a little strange .. Most of the time its email only that I can recall, or occasionally email+sms