I'm not completely sure, but I think title IX also has a criteria on roster spots and/or total expenditure. Sports all have a limit on their walk-on roster spots and I thought it was tied to cost/title IX more than competition, etc., but I could be wrong.
As far as replacing swimming with soccer, that could be a sticky situation, but not out of reason. I know that swimming is a sport that costs a lot and doesn't bring in revenue. Soccer on the other hand would at least lose less money. Byrnes has a history of cutting men's swimming at his previous schools even when they were competitive programs, so I'm sure he's thought about it here, too.
I think the 2 things keeping it at A&M are
1) I can't imagine that the athletic department is hurting for money, so that isn't a high priority, and
2) The state of Texas is one of, if not the best talent pools for swimming in the country. That would be like a north eastern school dropping lacross or a northern school dropping hockey. Because of this talent near by A&M will always have a competitive swim team, and with a little recruiting luck we might break through to an elite program.