I asked Symantec about that, so they sent me this link: https://knowledge.symantec.com/support/partner/index?page=content&id=NEWS10071&viewlocale=en_US
By April 18, 2017, Symantec will decommission the "Legacy"
timestamping service.
(Legacy) RFC 3161 SHA128 Timestamp Service:
https://timestamp.geotrust.com/tsa
To support business continuity for our customers, we have provided the
following replacement services.
(New) RFC 3161 Service SHA256:
http://sha256timestamp.ws.symantec.com/sha256/timestamp
Important: Customers must leverage SHA256 Timestamping service going
forward, and should not use a SHA1 service unless there is a legacy
platform constraint which doesn't allow use of SHA2 service (in this
case you can use this new URL: RFC 3161 Service SHA128:
http://sha1timestamp.ws.symantec.com/sha1/timestamp).
Background and Key Industry Mandates affecting the Timestamping
services
To comply with Minimum Requirements for Code Signing (CSMRs) published
by CA Security Council and Microsoft Trusted Root Program Requirements
(section 3.14), Symantec has set up the "new" RFC 3161 (SHA1 and SHA2)
service as per specifications and requirements laid out by section
16.1 which requires FIPS 140-2 Level 3 key protection. In the near future, Oracle will be taking steps to remove SHA1 support for both
Java signing and timestamping. This will not impact Java applications
that were previously signed or timestamped with SHA1 as these will
continue to function properly. However, Java applications signed or
timestamped with SHA1 after Oracle's announced date may not be
trusted.