I believe it will stay the same this year and then go up the following year - so we'll basically trail the NHL by a year. As such, you'll see the general contract demands of pending free agents fall in line with the past year versus the most current UFA market. If the admin team does decide to make the change, they'll have to do so before July 1st so team's know where they stand (similarly, NHL teams still don't know what the cap will be, so this isn't totally unrealistic).
In terms of restricted free agents, keep in mind most restricted free agents don't sign until July or August in the NHL. While plenty of RFA's have already signed contracts in the HFNHL, don't be dismayed by some of the demands when you're talking about offers of $450-$1 million - those are the guys hoping to get a RFA offer sheet. Obviously 90% of them won't, which will lead to their demands potentially curbing a bit, but for those who do get an offer sheet, it can mean a lot more money (especially with so many league minimum offers coming in). Also, keep in mind any NHL team can make an offer sheet of ~$650k without any compensation going back to the team holding their rights. So the question you need to ask yourself is this player of interest to another team at that rate? Are they waiver exempt so they can stay in the minors and only receive 10% of that salary? These are just a couple of considerations.
With respect to NHL salaries you reference, while they are definitely a consideration for market value, often these listed salaries don't include lucrative signing bonuses and also might be one-way deals. Meanwhile in the HFNHL, there are no signing bonuses and all deals are two-way, so a $500,000 contract offer might just mean $50,000 for the guy in the HFNHL, where as in the NHL, a $450,000 contract might be one-way, so they can almost 10x as much money. Or, it is a two-way deal and included $100,000 SB so they still get 3x as much money. These are just a couple of the considerations.
The last consideration is obviously performance. If a player earned the league minimum this past year in the NHL, but scored 20+ goals, don't be surprised if they reject the 10% mandatory raise you offered them, even though their NHL salary from this PAST season was league minimum (and you cry, 'but that's what they make in the NHL!'). They are poised for a major raise at their next NHL contract and we all know that. What is particularly baffling is GM's offering a 4 year deal at the 10% raise, which doesn't make much sense for the player at all, at least for the player who just had a great break through type year. The good news is once you do sign a player, they don't ever hold out or demand a new contract in the HFNHL, no matter how unjust or how long the contract is for. Just look around at some of the contracts and you'll see where GM's timing was very good in getting a guy to sign long term. Reggie makes sure NO clients hold out, so give him that much.
What is MUCH more relevant than their past contract is when a player re-signs with their team in the NHL at a certain rate for next year. With that as a reference, you have a very strong case to get the player to sign a similar deal in the HFNHL.