In terms of no cap until the following year, that's not true either, I think there are off season cap rules.
According to capgeek.com you're right:
Teams can exceed the salary cap's upper limit by 10 percent during the off-season. The following count toward the team's cap payroll:
- All players on one-way contracts, regardless of where (or if) they were playing the previous year.
- All players on two-way contracts, in proportion to the number of days spent on an NHL roster the previous season.
- All restricted free agents who have been extended a qualifying offer (while the offer is valid), with one-way qualifying offers counting in full and two-way qualifying offers counting as described in No. 2.
- All restricted free agents signed to an offer sheet (such players count against the team extending the offer sheet while it is still valid).
- All buyouts.
Example: A player with a cap hit of $500,000 and signed to a two-way contract was on an NHL roster for 94 days in the previous season, which was 188 days long. During the off-season, he will count [$500,000/188] x 94 = $250,000.
Example: A player with a cap hit of $1.25 million and signed to a one-way contract was assigned to the AHL in the previous season and spent no days on an NHL roster. The player will still count $1.25 million during the off-season.
Please note CapGeek.com does not yet calculate the off-season cap. Our off-season cap estimates are a projection of opening-day cap space.