While I think getting slides in on time is great for a lot of reasons, reading
the slides early isn't that important. What is important is that remote
people see the slides at the same time as local people. For that, it seems to
me that Meetecho support does exactly what is needed. You just follow the
slideshow online, along with the audio.
Of course, in order to have Meetecho support, you need the slides in advance of
the meeting, preferably far enough in advance that it doesn't create a massive
hassle for the Meetecho team. But by making Meetecho the place where the slides
are presented, you ensure that everybody is on an equal footing, without
engaging in punitive behavior.
The main reason to want to see the slides in advance is so that the working
group chairs can evaluate them to see if they will actually be a good use of
time. But that's completely orthogonal to the remote participation issue.