JDK-8191438 adds some new warnings and information text. This jarsigner tooldoc file should be updated.

Severe Warnings:

hasExpiredTsaCert
Code 4. The timestamp has expired.

tsaChainNotValidated
Code 64. The timestamp is invalid.

Informational Warnings:

hasExpiringTsaCert
The timestamp will expire within one year on YYYY-MM-DD.

Please also update the example to include the new expiration information at the end of signing and verifying (with -verbose).