It depends. If the issuer keeps the "issued" date the same, no impact. If it resets, you will lose the time that card gave you.
I have seen card's issue date get reset when the same company needed to send a new card due to a store hack. And I thought "really?" My FICO gets dinged because average age dropped when I did nothing at all on my end? More recently, Costco dropped Amex as their preferred card and went to a Citibank Visa. The Visa retained my original date. I was amazed at this.
So, from my own strange experiences, it can go either way. This points towards the benefit of having multiple accounts and building an aging credit file.
FICO likes to see over 9 years for the average age. Over time, I've been careful not to get new cards or cancel old ones too quickly. At close to 10 years, a dropped card or age-reset will not drop me below that 9 year level. And the recent card I picked up also didn't pull the age down more than a couple months.