So this is what Fortnine said:
" Thank you for taking the time to reach out to the FortNine team.
We are unable to check and guarantee tire manufacture dates because we don't physically stock tires at our warehouse location. We receive tires directly from the distributors once they are ordered from us, and they are shipped directly out to the customer once we receive them. This ensures that we get the freshest tires possible, and that you receive your order as quickly as possible.
Motorcycle tires do not become stale or compromised from storage, as long as the storage space has sun coverage, and is maintained at a reasonable temperature. Our suppliers store the tires in this way.
Most tires that leave our warehouse are between 6 months to three years old, although some less popular, or discontinued tires may be older than that."
Should I care?
Shep