I'm not sure if it would help, though it might. It sure would bring Winter Olympic attention to countries like Kenya and Ethiopia, where currently I'm sure next to nobody cares about the Winter Olympics. It also might bring some attention to cross-country from parts of the world that don't even realize it is a sport. I'm sure just fleeting attention, much like the attention Americans pay to T&F during the Olympics, but isn't getting people aware that the sport exists an important first step?
Another question about the whole proposal that I've offered a few times: why is cross-country not an Olympic event anyway? It's a great event that deserves a spot at the table far more than a lot of the events that are already on the Olympic program. Whether summer or winter (winter is an interesting thought) cross-country belongs in the Olympics.