Don't forget that in Y9, Y10 and Y11 we will likely see Heiskanen jump over the other three again since he will need a new deal under a much larger cap and the others will still be signed.
When the cap goes up, cap hits will follow. The expectation of growth is different, but Heiskanen is in line with Ekblad (~$8.15 mil x 8 adjusted for inflation), who was in line with Pietrangelo (~$8.24 mil x 7 adjusted for inflation). Pietrangelo's real AAV went up ~35% on ~27% growth 2nd contract to 3rd contract.
The flip side is that Dallas or another team will make a long-term commitment to a 30 year old Heiskanen instead of a 32 year old McAvoy. There are pros and cons to each pathway.