I don't think it's likely at all.
Here's a perfectly reasonable scenario:
- Harris is on phone A with the earbuds plugged in. Maybe to Biden? Idk, doesn't fucking matter.
- Someone else calls on phone B. Maybe it's an aid's phone? who knows. Doesn't fucking matter.
- Who's called on phone B has important information. So she puts it on speaker and sets it on the table, putting phone A in her lap or pocket. Now the earbud cord goes to her lap.
- Now she can talk to both whoever is on phone A in the bud and Phone B who's on speakerphone.
- Phone A can hear what information phone B has to convey because the buds have an open mic and they don't need a middle man to tell them what phone B had to say about something.
This is a very simple premise, one that most normal people can come up with who aren't obsessed with conspiracies and explains whatever Trump is asserting here in a much more reasonable way than some clandestine plot for a psyop.