Unless there is some immediate need, Find a better distributor. There is no reason to buy 10 Y.O date codes of an active part. It is more trouble than it's worth.
That being said, properly stored and cared for IC components will be fine to mount after 10 years.
The key here is properly stored. With older parts that pass through several hands there is a real possibility that someone screwed up. Unless you have proof positive of their condition and storage (usually certificate from the reseller), it is more trouble than it's worth for production use.
It looks like you are doing spot buy from a re-seller, likely not officially authorized distributor of Microchip who would not hold old lots like this. If the existing distributors do not suffice, Contact microchip directly and ask for assistance sourcing QTY 1500 of this device, they are friendly and will provide you a rep to talk to that will help. Email them!
Most of the other answers are based on the technical feasibility of these chips being OK, which to me is not relevant. Those guidelines apply when you can guarantee good storage practices going back to when the parts were first sold. You have no idea how many hands it has passed through or how they stored it unless distributor is willing to certify to that. I like @Bimpelrekkie answer because he frames it as the commercial issue that it is.
Lacking that, this is a bad idea unless you are prepared to test, your CM/EMS may or may not be able to help you with this. It is a massive headache and not worth it (IMO) unless you don't care or are desperate.
Moisture dots can be changed, leads can be cleaned or poorly replated in a non-obvious fashion, parts can be re-reeled, silkscreens re-printed, and labels restickered.
Things I have personally seen that have gone wrong in this situation when using second market parts.
Captive Moisture leading to part failure during reflow or soon during operation
Lead corrosion due to poor storage.
Old stepping or revision with subtle issues that you did not qualify in the design.
(Always Read the Chip Errata!, best one I found so far was a memory
IC with erata that read "ECC on this ECC part never worked, fixed in
rev B.", discovered due to high corruption rate when using Rev A part due to shortage)
What I have done in this situation to mitigate when there was simply no way around (Obsolete part, global shortage, cash strapped startup)
- Always Get Samples
- Read the erata
- Contract with distributor on guaranteed refund in case of non-usable parts
- Give to 3rd party lab to examine carefully
- Have CM/EMS perform extended bake-out and solder ability tests
- Decapsulate and image IC compared to new lot.
- Carefuly test first PCBA articles using suspect lot