Aircraft flying at high altitude have a fairly high pressure differential inside vs outside. A cracked windshield is a routine event, not common but not uncommon. Windows are at least 2 ply, sometimes 3 or 4 ply, and a single layer crack does not result in a loss of cabin pressure.

It does increase the risk of additional cracking (or of departing shards entering an engine) so the SOP for a large crack is to reduce cabin pressure. The most comfortable way to do that is to decrease altitude and to land in an orderly manner.

Unless there is more information released, this is a non-event and no reason to suspect anything other than an ordinary mechanical failure.