Firstly, would they want to see the body of the former president bastardized or vandalized by zealots? It could happen. Of course, this is a remote possibility since the Libingan is a highly secured facility? Really? Not if the attack comes from "on high" or several kilometers away?
Second, yes, Marcos had achieved something like a mythic personality since his interment there in the Ilocos. The Marcos mausoleum in Batac had become something like a shrine, and attracted several tourists, which, through the years, had helped changed the perspectives of several Filipinos who come to the region for relaxation. The mausoleum is now one of the most visited places in the Ilocos.
If it disappears, the memory of the former president would also begin to dissipate, slowly at first then after say six years, it would eventually disappear, like a wafer disolving on water. Without animated talk, myths are often relegated to the back of people's memories.
Besides, will they allow Marcos to be buried alongside other presidents? If I'm asked, I would say no. Why? People would definitely compare his administration with those of his predecessors, and it would be an endless cycle of delicious throw-backs always coupled with nightmare hugots. Right now, apologists of the dictatorship are very active on social media spreading both disinformation and highly contentious talk about their idol. With Marcos buried at the Libingan, people would definitely be discussing real issues and of the truthful things Marcos did when he was still alive.
Will talk about his father help Bongbong's electoral dream to Malacanan in 2022? If Bongbong would just rely on surveys, obviously, the former senator would probably plunge himself headlong again and fail the second time. Why?
Sometimes, surveys do not show emotions or views underneath those survey results. Every pollster knows this--that every single time they go to the field and mine data from Filipinos, they find it difficult to ascertain the "real score" even from a wide field of respondents. That explains why several analysts often give their clients erroneous advice because they often base theirs from surveys which results come from questionable mining of facts.
Again, let me caution the Marcos family from this plan of allowing the burial of the former president at the Libingan. Just heed the advice of several well-meaning friends---just bury the family patriarch beside his loving parents in Ilocos Norte.