Has Bombardier addressed this accident yet in any briefings to operators?
Yes, an Advisory Wire was sent out on 26th December. Challenger operators should have received it, and it's also available via the Bombardier customer website for operators with access. It adds little to the statements in the media and the various news items linked to earlier in the thread (bear in mind it went out within 24h of the accident) but does state that the local authorities have notified TSBC, to whom Bombardier have offered assistance, as is customary for any OEM.