That is an astute observation.
The government is obviously trying to intimidate the people who are supplying the truckers by threatening them with arrest. They are banking on the fact that the supporters will become frightened at the prospect (of arrest) and go home.
However, if thousands of people continue to show up with fuel and sandwiches and not fear a night in jail, there will simply not be enough jail space to house them all. Outside of a Tiananmen Square type massacre, the people have the power here and will prevail if they have the fortitude to go to jail for their beliefs.
This kind of civil disobedience is what drove the civil rights movement. If people were afraid to go to jail and so stayed in the back of the bus (so to speak), nothing would have changed back then.
Same deal with Indian independence.
Of course, this only works against an authority with a conscience. Try that Satyagraha stuff on Nazis or Chicoms, and the mass graves will be filled, but not the jails.
The British tried to act like that one time at Amritzar, and as a result, they had to let India go eventually.
So history’s repeating itself. I’m betting that the RCMP have a conscience and are therefore susceptible to satyagraha. Aside from that, doing a Tiananmen Square or Amritzar-style massacre on truckers is a non-starter. The people can take cover behind a truck if they start shooting, and if you hit a gas tank, some RCMPs will likely get hurt.