Johnson had great advanced metrics down the stretch, just that every mistake went into the net, which is more on the goaltenders than anything else. He's limited at this point in his career, but can give you 12-15 minutes a night and more if you use him every third game.
He'd be used similar to Staal last season, pair with Zamula or Ginning as a veteran nursemaid. As a RHD he's also insurance for injuries with Drysdale (coming off surgery) and Risto (injured every season).
This does suggest they don't have a lot of confidence in Attard, while Samson and Grans are destined for LHV.
Andrae will either start every game (which means they'd probably deal Zamula) or start the season in LHV.