He doesn't think ahead and concoct plots; he reacts to whatever is threatening his ego on a particular day. Right now he's pissed off because McConnell couldn't round up enough votes for a repeal of the ACA, which embarrasses Trump because he promised it would be repealed on the first day of his administration. This hurts Trump's snowflakey little ego, and when that happens he lashes out at whoever he thinks is responsible (in this case McConnell) so he's trying to embarrass McConnell by blaming him and demanding he end the filibuster.

There is a law on the books for that which can be repealed with the end of the legislative filibuster would provide an opening to stack the courts.

and it didn't work out well. https://en.wikipedia.org/wiki/Judicial_Procedures_Reform_Bill_of_1937

If the filibuster is eliminated and he learns that there is only a law limiting the number of supreme court justices. You can bet he would put pressure on the republican senate to repeal the law so he could stack the courts in his favor. Rather or not republicans would go for that. Who knows? I wouldn't put it past them though.

That's how Gorsuch got confirmed.

They only ended in the case of nominating supreme court justices. There is currently a law that limits the number of supreme justices. End the legislative filibuster and that law could be repealed and boom court stacking.