This was an amendment to the by-laws that went into effect last December. Presumably this was after the couple bought their condo unit. If so, this is a change in the terms and conditions after the purchase.
The HOA is an ongoing form of neighborhood self-government. You can't complain about the "temrs and conditions" changing any more than you can complain about the local school board raising taxes.
Rules are rules and people who buy homes in an HOA voluntarily agree to continue to live under the governance of the HOA.
SD
The terms and conditions specifically stated that the HOA could amend its bylaws at any time.