[SSL] Add SXG impact to Digicert migration guide (#18566)

Author: RebeccaTamachiro

src/content/docs/ssl/reference/migration-guides/digicert-update/index.mdx

@@ -24,19 +24,22 @@ The SSL for SaaS renewals offboarding has been postponed and started gradually r
 
 ## Scope
 
+
+### Certificate types
+
 This migration only affects [Universal](/ssl/edge-certificates/universal-ssl/), [Advanced](/ssl/edge-certificates/advanced-certificate-manager/) and [Cloudflare for SaaS](/cloudflare-for-platforms/cloudflare-for-saas/) certificates where the certificate has been provisioned by Cloudflare using DigiCert as certificate authority.
 
 Also, this change will not impact existing certificates issued from DigiCert that Cloudflare is currently serving, but it will impact new certificate orders and renewals.
 
 Consider each specific migration guide for actions you might have to take and refer to [CAs and certificates FAQ](/ssl/edge-certificates/troubleshooting/ca-faq/) for commonly asked questions about the Cloudflare offerings and CAs that are used.
 
 :::caution[Not affected]
-
-
 Cloudflare [Origin CA certificates](/ssl/origin-configuration/origin-ca/), Cloudflare [mTLS client certificates](/ssl/client-certificates/), and [custom certificates](/ssl/edge-certificates/custom-certificates/) **are not** in the scope and thus not affected by this migration.
+:::
 
+### Other products and features
 
-:::
+As of December 14, 2024, [signed exchanges (SXG)](/speed/optimization/other/signed-exchanges/) will no longer be supported for [punycode domains](https://en.wikipedia.org/wiki/Punycode). This is due to a [limitation of Google Trust Services](/ssl/reference/certificate-authorities/#google-trust-services), which will be the only certificate authority (CA) used for SXG.
 
 ## Dates reference