This would be a warranty issue under the uniform commercial code. The usual remedies exist. Sometimes contacting your consumer protection agency can help.

I can make up legitimate reasons for delay, but they seem a bit hollow. The delayed shipping date appears a bit far out there.

The entity you bought the tires from is really in the middle, but might be another route.

I would file a polite and thorough complaint with my consumer protection agency. Point to the published warranty http://schwalbetires.com/company/warranty_policy and ask the agency to follow up.

I suspect they had to thoroughly investigate what led to the problems, redesign production for those tires, and then get the tires made. I could see that taking 2 or 3 months, including shipping. The issue is getting a bit long in the tooth at this point!