That's not really the "seal" but more of a "trim ring". they shrink over time and it may have been cut short at the window factory. Easy to replace as long as you have the correct "profile" as there are a number of them. May fall under the warranty.
2012 Copper Canyon 273FWRET being towed by a 1994 Ford F350 CC,LB,Dually diesel.
Airlift 5000 bags, Prodigy brake control, 5 gauges on the pillar.Used to tow a '97 Jayco 323RKS.
Now an RVIA registered tech. Retired from Law enforcement in 2008 after 25+ yrs.