when they are discussing hypotheses versus relatively solid science-based conclusion.
When they don't know yet - because they are being asked to hypothesize on an issue for which there is not data-based relative certainty, they say (as you did quoting the article) "there is no data to suggest. . . "
As in these previous hypotheses:
There is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection. WHO
WHO: There is currently no evidence that wearing a mask (whether medical or other types) by healthy persons in the wider community setting, including universal community masking, can prevent them from infection with respiratory viruses, including COVID-19.
On January 14, the World Health Organization (WHO) tweeted that there was "no clear evidence" that the coronavirus could spread between people.
The assertion (which you are reporting as certainty "It cannot" ) is phrased in the manner they phrase things they are not yet certain of ("the CDC explains it has no data to suggest this new coronavirus or similar coronaviruses are spread by mosquitoes or ticks" ).
So - yes, we can (and have) learned many things - such as that each and every one of those hypotheses turned out to be false. But apparently one of the things not yet learned is how to read weasel words. Until there is data, it is just a hypothesis (not a certainty, or even a probability) - and the CDC/WHO will phrase its statements cautiously so that if/when it is proven wrong they can point to the hypothetical phrasing.