If you look at the article there isn't any one claiming that tplink is in bed with the prc. Unlike say huawei or zte. It's not even that they're saying tplink could be compelled to give up data like alibaba or tencent.

Rather, it's that tplink has security vulnerabilities and those along with all other factors make it a national security threat. Other factors include, how pervasive it is in the market and how actively the Chinese are exploiting these flaws.

And to your point- soho devices are notoriously insecure, tplink especially. If youre not familiar then you simply must take your expert's advice on it.

This is more about preventing the next vpnfilter