The HOA is the defendant, so basically all owners are.
The hope was that the serving lawyer could cancel it somehow, but I don't know if they have that ability.
Carefully read the papers you were served with. In every state where I've served a subpoena, there is an attached document about your rights as a witness. It explains who you should call/contact if you can't appear. In my state, it includes an "objection" form, which you can use to explain that the subpoena places an undue burden on you. Google [state] + Notice to Person Served with Subpoena, and its variants, if you don't already have an objection form. Call the HOA's lawyer to see if he or she will help you get it worked out. I'm guessing that this is for a deposition, not trial, so this should be something that can be pretty easily worked around your schedule.
Send another email to the plaintiff's lawyer, explaining that you WILL be leaving for Asia, and that you're happy to reschedule for after your trip, but you will NOT be attending the deposition because its an undue burden. If you are going to have email access on your trip, tell him that so you can communicate with him after you leave on Wednesday and get something rescheduled for after you get back.
In my state if you did all of this and the plaintiff's lawyer didn't work with you to reschedule, they would be the one in trouble with the judge, not you.