WiredTiger btrees (using the non-disagg block manager) always create stub files on disk, leaving the file descriptor open, it stays open until the btree is closed.  This is not appropriate for ingest tables (they do use the non-disagg BM), which will never write to disk.  At minimum for this ticket would be to allow the stub file to be created, but then close it immediately.  The better outcome would be to not create the stub file at all.  It's hard to know if there would be any complications to doing that, there may be certain expectations by the block manager.

See related WT-17323.