No longer able to override vanilla block loot tables as of 1.16.100

• Partner Rank: 1
• Partner Team Reporting: Meatball
• Verification Build: 1.16.100.01 RC1
• Summary: As of 1.16.100 you are no longer able to override vanilla block loot tables.
• Impact: This results in a major loss of features that previously worked on a map slated to be released. This is currently causing a delay in the release timeline while we sort out the future of this feature.
• Repro Steps:
  1. Download and install world provided to Gregg in our partner chat
  2. Load world and and enable cheats.
  3. You will see a content log error reporting on the failure to register blocks with names matching vanilla content.
  4. Give yourself a diamond pickaxe and a stone block, and break the stone block with the pickaxe.
  5. Vanilla loot will drop from the broken block.
• Repro Rate: 10/10
• Observed Results: Instead of the block dropping from our custom loot table, it falls back to the vanilla loot table.
• Expected Results: The block would respect the override and drop from our custom loot table.
• Screenshots / Videos Attached: Yes, see attached video
• Regression Builds: This worked up until 1.16.10.02 RC1. It has been also tested on the 1.16.100.04_rc4 and confirmed to be not working here as well.
• Notes: This involves a soon-to-release piece of content so we uploaded the world to our partner channel and pinged Gregg.