SharePoint Online Enterprise Content Types Not Using The Content Type Syndication Hub

1) You could provision the content type in code via CSOM and push it to multiple sites

2) You could use site designs and add new content types automatically like below

https://docs.microsoft.com/en-us/sharepoint/dev/declarative-customization/site-design-overview

{
"$schema": "schema.json",
"actions": [
{
"verb": "setRegionalSettings",
"locale": 1033
},
{
"verb": "createContentType",
"name": "Test Content Type",
"parentName": "Document",
"parentId": "0x0101",
"id": "{1B1AF0B2-14B0-41C2-8273-DBD2C3F0DB8E}",
"subactions": []
}
],
"bindata": {},
"version": 1
}