The situation is more complex than that. First, historically the racist far right in Bolivia was just aching for a reason to kick the indigenous president out (there is a now deleted tweet by the now semi-legally acting president outright stating she doesn't like "Indians". The far right Camacho, one of the key instigators of the coup, vowed to "never again let the Pachamama in the government"; the Pachamama being an indigenous and non-Christian deity). Second, while it was legally dubious for Evo Morales to run for a fourth term, it was deemed legal by a court from Bolivia and it was accepted by the OAS (yes, the same OAS which later claimed there were "irregularities" with the voting -- so this isn't an organization that particularly sides with Morales). Finally, before being kicked out (er, "suggested by the military to resign", which in Latin America carries ominous undertones), Morales had finally accepted to have completely new elections, as suggested by the OAS. By this point the instigators of the coup had already seen they had the upper hand and accepted nothing less than the president's resignation.

So no, the re-election of Morales was not the cause of the coup. It was merely an additional argument they used to force him out.