Athletic aid is awarded for exactly one academic year, with a few well defined exceptions, such as the player is graduating midyear, etc. Awards can be increased but not decreased during the academic year (actually after the NLI signing date or after July 1 for renewals). There is no explicit requirement for the college to apply the benefit on a per term basis, but practically it must be done that way.
The rules don't specify the terms of an award, nor do the rules distinguish between tuition or room and board. Books are separately accounted for. It's up to the college to decide whether the award is lump sum or a percentage of e.g. tuition, or percentage of an equivalency or perhaps even a percentage of the total cost of attendence.
For a percentage award, if tuition goes up mid-year and there wasn't a compensating decrease in some other cost associated with the percentage, then I think the actual dollars have to be increased mid year to hold the percentage. For most players, who are on a partial scholarship, the bill to the student is still going to increase. For players with a dollar amount agreement, if the dollar amount was 25%, then I think the dollar amount would also have to increase.
I'm surprised that a college would increase tuition without previous announcement or planning. But if it were a planned increase, then I think the athletic department would have structured that into any agreement with the player.