Interesting to look at Koskinen's game splits:
https://www.nhl.com/player/mikko-kos...eason=20182019
He's been below average on the road (6-5-1, 3.23 GAA, .891), and his numbers are definitely trending in the wrong direction in December and January (after a stellar November).
The only reasonable explanation is that Chia left this offer open back in November and Koskinen's agent finally told his client to sign it, fearing Chia would get fired and his replacement would immediately take it off the table.