The importance of this is that, in order for an objection to an electoral vote certificate to be considered, it must be made by at least one member of each chamber. https://twitter.com/daniellamicaela/status/1338919144931127297

It was on this basis--the failure of any senators to sign objections made by members of the House--that Vice President Biden, presiding as president of the Senate, was able to summarily swat away objections ...

... made by some House Democrats to some of the electoral votes cast for Trump in the 2016 election.
https://www.c-span.org/video/?421237-1/joint-session-congress-certifies-donald-trump-us-president

If an objection is made by at least one member from each house, then both houses must repair to their respective chambers for debate and a vote, with the objection being sustained only by a vote of a majority of both houses.
https://www.law.cornell.edu/uscode/text/3/15

So basically McConnell is telling his caucus not to let the crazies in the House to make a circus of the electoral vote counting on January 6.

* let the crazies in the House make