Whether or not it is fact matters not in this case, SM has the right to exclude anyone they deem as unfit under their TOS.
But, my take on it:
He has been accusing democrats of stealing the election, without any basis in fact, or evidence, noting that he started doing it many months before the first ballot was cast, thus proving that it was not 'evidence' that so caused him to do this, it was a scheme to subvert the election. This is the first president in history to accuse his opponents of stealing/rigging the election.
By doing this, he has single handedly undermined confidence in the election, and to that extent, has damaged democracy itself. Every election has irregularities, and isolated examples of individuals cheating, but it never amounts to more than a few, and it always involved members of both parties. These do not prove the charge that 'Democrats rigged the election', but Trump knew that his fans would not be able to make that distinction, that they would believe his every word and thus Trump, in some 65 million people, and destroyed confidence in the election. It will take a long time for America to heal, it won't heal as long as Trump is fanning the flames of lies inspiring hatred of democrats.
His objective was to destroy confidence in the election to his fan base and in statehouses where republicans control the election apparatus in the hopes they would toss out Biden electors and replace with Trump electors.
Government officials currently are testifying in congress how he has repeatedly and persistently attempted to get the DOJ AG Rosen to announce the election was corrupt, so that he could pressure states to toss out Biden's electors. This scheme is being testified to by more than one official, not to mention we have recordings of this scheme in GA ( where he is being investigated for criminal activity in GA by the GA AG ).
This scheme was furthered by over 60 lawsuits, all of which no evidence to prove Trump's charge that 'Democrats stole the election' has withstood court scrutiny.
In the furtherance of this scheme Trump whipped up his base with cries of 'Democrats stole the election", staring months before 1/6 and up to 1/6, and has inculcated hatred of democrats to such a degree, like a volcano, that anger erupted into a juggernaut on Jan 6., where cries of 'Stop The Steal" were repeated over and over and over again, with malice on their minds, they also chanted 'hang Mike Pence". Trump attempted to stop the Congress's constitutional duty to count the state's vote and thus finalize the certification of the election, or at least delay it so, in the interim, he could pressure more states to toss out Biden's electors and replace them with his own.
Therefore, on 1/6, the overall 'riot' was due, ultimately, to the continuous incendiary acts, comments, mentions, speeches, on 1/6, and going back many months of which the predominant message was 'democrats stole the election' and that lie began before the first ballot was cast, inculcated in the minds and hearts of his follows long and hard, to such an extent, that it caused a welling up of a juggernaut of rage & hate, and erupted in volcanic fashion on 1/6, resulting in several deaths and millions of worth of property damaged, some property stolen, and trespassing of the offices of congresspersons and senators and the terrorizing of persons thereby, and the delay of several hours of the constitutional proceedings.
The point is, those who are asking for explicit speech on 1/6 are missing the larger picture. Heck, mafioso commit murders without so much mentioning the crime committed, so explicit speech is not required, Deeds, acts, speeches, over a period of time, creating a juggernaut of hate equals 'incitation of insurrection' 'seditious conspiracy' etc.