No, it can't[1]. However, vestigial marking of present-tense third-person-singular verbs is going strong and pretty much nobody considers the fact that it's completely useless as an argument against doing it.
The difference is that nearly everyone doesn't know the who/whom rule -- it is dead -- while nearly everyone does know the living pres.3sg rule, and they have trouble violating it even if in the abstract they might like to.
[1] The strongest argument in this direction is that no one in the modern day knows what whom means or under what circumstances it appears, meaning that when a whom is encountered it can only make them more confused.
The difference is that nearly everyone doesn't know the who/whom rule -- it is dead -- while nearly everyone does know the living pres.3sg rule, and they have trouble violating it even if in the abstract they might like to.
[1] The strongest argument in this direction is that no one in the modern day knows what whom means or under what circumstances it appears, meaning that when a whom is encountered it can only make them more confused.