That isn't true.
A blower isn't necessarily capable of internal compression (screw types are, Roots aren't) so what boost (or pressurisation) it creates is merely air queuing up to be ingested by the engine.
But that doesn't happen on a 2T because the air has a straight unrestrained path through the transfer ports and out the exhaust ports. No queuing, no boost, no supercharging - therefore the device supplying the air is a blower and cannot supercharge the cylinder to higher than atmospheric pressure.
The exceptions are where the exhaust ports close before the transfer ports - very rare, and by such a short period as to be almost inconsequential and requiring the complexity of mechanical valve control or, when there is significant back-pressure at the exhaust port. That latter possibility is why a turbine (of some form) extracting energy from the exhaust stream benefits a 2T engine - see Crecy and Nomad.
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