Note I work in a high growth industry where workload is unpredictable - on one week we could have a sudden surge in clients, and the week thereafter there's an unexpected calm.

If I had scheduled time off during a week (and maybe I am on vacation abroad), and suddenly there's a huge client - will it be unprofessional for me to be absent during those crucial initial meetings?

Or what if our CEO organizes an important social/teambuilding event for all senior employees during my holidays?

Should I try my best to attend those specific situations, e.g. come to the office on that day just for the client meeting, go to the social event just to say hi to the CEO?
Would it hurt my career prospects to be absent?

Or would I be "forgiven" for staying away?