PUP.Optional.WinYahoo in registry

Hello Jack,
We apologize for the inconvenience.
The registry entry can be caused if any file related with WinYahoo is opened. You can leave this as it is, if it does not cause any unwanted pop-up while browsing. They are not harmful in any way. AVG will not report this, because they are not harmful to your computer or if this program is installed with your permission.
Thank you.

Hello Jack,
We apologize for the inconvenience.
The registry entry can be caused if any file related with WinYahoo is opened. You can leave this as it is, if it does not cause any unwanted pop-up while browsing. They are not harmful in any way. AVG will not report this, because they are not harmful to your computer or if this program is installed with your permission.
Thank you.

Reading bad things about this registry entry
Keeps coming up as a finding with MalwareBytes.  HijackThis doesn't report it.  AVG doesn't report it.
Should I be concerned?