How did the board change the CCR and when was the CCR changed? Check your HOA bylaws to find out how the CCR can be changed. If the change requires a majority of home owners, did you get a notice and did you appear in the home owner meeting and vote? Request a tally of the votes from the HOA. These will determine whether the CCR change is valid procedurally.
If the CCR is valid, you still have a chance to appear before the board to request a variance. Granted or not, you have to present your best case why your leases should be upheld and why a variance should be granted.
The CCR written as is, there are loopholes. For example, your lease does not have to be approved by HOA but you have to provide the leases to the HOA. The CCR does not currently prohibit sublease. Not in this provision anyway. I am not saying you can intentionally violate CCR but before you sell the house there are many other ways to deal with this. And, you do need an attorney's help in this matter. Not something you can do it yourself considering the board is backed up with its attorneys.