Admission upfront - I'm a UK national transport journalist.
Now that's the way! Good.
I haven't seen anything here about whether ingestion of foreign objects from the runway might be a possible cause - is that a possibility or would you expect that to cause a problem immediately rather than the 10-15mins after take-off that it seems to have taken?
It's too early to say for sure but here's an engineer's guess. Theoretically possible, maybe, but likely, I should not think so. Anything ingested from the runway should have damaged the fan first, and I could see no sign of that. Once they've inspected the engine you'll have your answer I presume.