Absolutely no.
First of all, it’s a great opportunity for some players to earn new contracts or be seen by other/better leagues.
Second, some NHL clubs would be against players going in July or as some suggest - September, cause noone wants to risk injury right before training camp/season start and probably players would hesitate to participate.
Third, as people above say - for European leagues the season ends in mid march, playoffs around mid April, so waiting til july and not being in best shape would potentially have a higher risk for an injury.
Four, tho not every year, there are other sports events in summer/september , especially since in IIHF worlds most participants are European teams. So there’s Football (Euro cup or Fifa world cup) in June/July, summer olympics in august, and Basketball tournaments in End of August/start of September.
From broadcasters views and ticket selling May is absolutely best month for IIHF worlds. So as others said, i suggest starting NHL season maybe in mid-September