Doesn't sound like a very impactful change to me.
However, I noticed today that Yahoo sent me notice in December of a SECOND large-scale hack in which my e-mail, including my password and security questions, were stolen. Fortunately, I pretty much moved off of yahoo a couple of years ago. It remains as an e-mail address for things that aren't very personal. I check it periodically. So, maybe the change will make for a better run company.
I STRONGLY recommend changing your personal e-mail address every couple of years at most (every year is better.) Changing to a different e-mail provider is best of all. There's no reason to let one company have so much of your life story. I recommend zoho.com, myway.com, ieee.org (if you qualify), mail.com. Gmail and Yahoo are necessary for some things (if you put videos on Youtube, you MUST have a gmail account) but these two companies are just too big. Also, Google is a vile spy organization that is possibly more powerful than the C.I.A. That increases the risk, imo, so I recommend going with smaller, reputable companies.