DM: I’ll need to know the identity of the author in order to respond. So far this is a thinly sourced story of unknown veracity. Given that, even if there’s some שׁורשׁ of truth, it may be considerably divergent than presented.
Either way, as Milhouse proffered the suggestion of honoring people who protect Jews certainly isn’t remarkable; normally that indeed would be highly commendable. The reason why many gedolim are on the record opposing any commemoration of any Israeli state organs, including Tzahal, is because of the heretical nature of the state. That’s before even getting to Tzahal’s particular longtime reputation of plentiful unchastity in their mixed gender barracks.
Additionally, even the story of RSZA as quoted in no way shape or form indicates an endorsement of “Yom HaZikaron” or suggests that they be honored more on Yom haZikaron than any other day of the year. AIY’s suggestion that the date was chosen due to Kfar Etzion doesn’t bear historical accuracy. The Israeli Kenesset’s website says this holiday was originally the same day as Yom Ha’atzmaut (independence day) but military families wanted their own day so it was changed by Ben-Gurion to be “marked one day before Independence Day, emphasizing and symbolizing the connection between the fallen and their devotion, and with the establishment of the State of Israel.” (Quote from Israeli Kenesset website.)
So the date of Yom HaZikaron itself was chosen to be directly associated with the establishment of the Zionist State; not for any noble reasons or yahrtzeits. Additionally, even though it isn’t the case but hypothetically if it had been selected to commemorate a particular battle where soldiers were lost, that the date was selected by heretics over any other date that also has yahrtzeits would still afford their selected date no significance in Judaism or for Jews.