Do you mean it's not a bad idea to use the idle upload bandwidth to distribute the updates, i.e. turn each PC into a bittorrent seed?
In theory it's pretty great, in practice, with metered connections you're using up the users internet quota and causing a lot of frustration.
I am used to unmetered internet connections, and after moving to the UK I've spent a lot of time investigating why I'm getting an insane amount of packet loss. I'm talking 30% on weekend evenings.
Long story short, a flatmate was uploading data all day without noticing, the ISP's traffic management kicked in, limited our bandwidth, buffers aren't infinite so packets get dropped [1].
As someone said in a similar thread, this may be the reason for ISPs to drop traffic metering and upload quotas, but I somehow doubt this'll happen.
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1: I've fixed it by limiting the upload quota and bandwidth on my OpenWRT router for that user. I guess I'll have to enable this rule for all other Windows 10 users in my house now.