In the Talmud Brachot 35b a dispute is recorded between Rabbi Yishmael and Rabbi Shimon Bar Yochai.
Rabbi Yishmael holds that you should act according to the natural way, such as harvesting your field in the time of harvest, while in your free time you should learn Torah.
Rabbi Shimon Bar Yochai objects and claims that being too involved in those activities for a livelihood will detract from Torah learning. Rather, learn and we will receive a blessing of others engaging in activities of livelihood on our behalf, such as in the situation described in Yishayahu/Isaiah 61:5.
Rabbi Shimon Bar Yochai was so involved in learning Torah that he would not even stop to pray Shmoneh Esrei, in order to avoid stopping his learning.
I do not think that he of all people would be happy of the 2 days of loss of Torah study that was caused this year on his behalf.
Perhaps one could contend that for the important mitzva of honoring a Torah scholar and also to educate the public not to respect those equivalent of the Romans (which is why he had to hide in a cave), Rabbi Shimon might not be against the 2 day break from Torah study this year done to honor him. I believe this is probably not true, because it says in the Talmud tractate Shabbat 119b (Soncino Translation)
Resh Lakish said in the name of R. Judah the Prince: The world endures
only for the sake of the breath of school children. Said R. Papa to Abaye, What about mine and
yours? Breath in which there is sin is not like breath in which there is no sin, replied he. Resh Lakish also said in the name of R. Judah the Prince: School children may not be made to neglect [their studies] even for the building of the Temple. Resh Lakish also said to R. Judah the Prince: I have this tradition from my fathers — others state, from your fathers: Every town in which there are no school children shall be destroyed. Rabina said: It shall be laid desolate.
The Poskim also bring it as halacha that
School children may not be made to neglect [their studies] even for the building of the Temple.As far as the issue of pushing off the Lag BaOmer festivities by one day and thereby causing school children to lose Torah study for the benefit of minimizing Sabbath desecration, it seems at first glance that we should apply the principle brought by the Mishna Brura that we do not do a smaller sin to prevent someone from committing a bigger sin.
But perhaps, you might want to answer back, that due to the honor given Rabbi Shimon Bar Yochai, etc. maybe we shouldn't call this a black and white sin.
Or maybe you will find some other reason not to apply the principle of the Mishna Brura that we don't do a small sin to prevent someone from committing a bigger one.