Not to be a Debbie Downer.
But with how they been doing the MCU, the Herbie robot will come off as more to appeal to children than adults and just be annoying.
Similar to how George Lucas did with Jar Jar Binks.
Also, Herbie was first introduced in the 80s Fantastic Four Saturday morning cartoon. He was like “Orko” from He-Man, just as annoying.
Marvel then introduced him in the comics as a more serious character, but being they have to introduce Franklin as a child, Herbie will most likely be his “babysitter”, it just isn’t going to work.