This precision strike should thoroughly demonstrate to Hamas' leaders that their days are numbered. Sinwar will be forced to scramble as one of his main advisors has likely been neutralized. The group is now one step closer to defeat, and the military is effectively applying pressure on Hamas that will directly translate to further concessions in hostage talks.
Israel has provided no evidence that this strike targeted Deif, and it's more than likely that this was a desperate move to derail negotiations and score political points. Both a gas complex and a water desalination plant were hit, making it seem that Israel's real intention was to worsen the already bad humanitarian situation in Gaza. Such genocidal violence wouldn't be possible without shameful US support.