mate-sensors-applet has previously been forked to not suggest a package which in Debian contains nonfree code (see T222).
PureOS however do not ship nonfree packages, and the suggestion is therefore - in the context of PureOS - not promotion of nonfree software but merely "promotion" of non-existing (and therefore undefined regarding freedoms) software.
Please reset to again track the Debian-shipped mate-sensors-applet package.
Yikes, looks like this issue fell through the cracks completely, sorry for that.
2019-03-24 07:27:13 - INFO: Imported 'mate-sensors-applet_1.20.3-1.dsc' to 'landing/main'. 2019-03-24 07:28:21 - INFO: Imported 'mate-sensors-applet-common_1.20.3-1_all.deb' to 'landing/main'. 2019-03-24 07:28:22 - INFO: Imported 'mate-sensors-applet_1.20.3-1_amd64.deb libmate-sensors-applet-plugin-dev_1.20.3-1_amd64.deb mate-sensors-applet-common_1.20.3-1_all.deb mate-sensors-applet-nvidia_1.20.3-1_amd64.deb libmate-sensors-applet-plugin0_1.20.3-1_amd64.deb' to 'landing/main'. 2019-03-24 07:28:24 - INFO: Imported 'libmate-sensors-applet-plugin-dev_1.20.3-1_arm64.deb mate-sensors-applet-common_1.20.3-1_all.deb libmate-sensors-applet-plugin0_1.20.3-1_arm64.deb mate-sensors-applet_1.20.3-1_arm64.deb' to 'landing/main'.
Thanks!
No problem with processing delay: Had it been urgent then I would have shouted louder :-)