Should I be concerned?

If we have not yet been given a firm start date for our FT gig (just a vague "late summer" sort of thing), should we be worried about getting our offers pulled bc of COVID? I emailed HR last month and they said that was still the anticipated timeline and they will confirm later, but I haven't heard anything since and don't want to be a pill about it by emailing again less than a month later (or would that be okay given the circumstances?). This is a fairly reputable MM bank if that helps.