I have been wondering if the two characters were related! I at first assumed so. But no mention of it in the film and none I could find online. Seemed like an odd choice to give him the same name if they are not.
Of course, it's because they're both pre-existing comics characters who were created generations apart and were never intended to be in the same work. Thunderbolt Ross was created by Lee and Kirby way back in the debut issue of The Incredible Hulk in 1962 (and was previously seen in the MCU Incredible Hulk movie), and Everett K. Ross was created by Christopher Priest and Kenny Martinez in 1998 (actually debuting in Ka-Zar before becoming a Black Panther supporting character). Everett's Wikipedia article actually says it has "not as yet been revealed" whether he's related to Thunderbolt.
But yes, it is kind of awkward that they both happened to end up in closely associated roles in the same movie.