It is certainly encouraging news, although anecdotal rather than scientific.
globally there doesnt seem to be massive spikes happening -but then that may because most countries have social distancing in place which although relaxed are still much more now than before restrictions started when the virus was spreading
"In stark opposition to Bassetti’s and other doctors’ statements, Italian public health
officials and the World Health Organization (
WHO) warn there’s no evidence to support
these claims. They urge health care providers and the public to continue to take the virus extremely seriously. Meanwhile, Bassetti says proof is on the way."
"It could take generations for enough genetic change to take place to substantially weaken a
coronavirus -- both the one that causes COVID-19 and other forms that were around before it. Human
coronaviruses are known to be extremely stable in their genetic makeup. They change
very little over time."
https://www.webmd.com/lung/news/20200603/claims-of-a-weaker-covid-19-virus-disputed