you can argue whether they maybe should tone down the noise a little but the health benefits, both physical and social as well as even the capital benefits, from the article:

"China is home to an estimated 100 million dancing grannies. Square dancing allows older women, many of whom live alone or with younger family members who they accompanied on a move to the cities, to socialise. They form strong bonds, often shopping or doing other activities, including group investments, together, the South China Morning Post reported"

are most likely very, very high and almost certainly underestimated. The kind of social security that comes out of having these kinds of relations well into old age probably saves society an incalculable amount of resources compared to the risk of social and financial isolation if these women could not meet.

Maybe find a way to make the grannies a little less militant but you would be straight up foolish to not encourage the elderly to socialize.