In SCI, e.g. in Anterior cord syndrome will it be bilateral LMN paralysis at the level of lesion and bilateral UMN paralysis below the level of lesion?

Except for hemisection injuries (see Brown-Séquard injury) where distinct neurological manifestations occur on either side of the body, the majority of spinal cord injuries have bilateral affectations. [1] Your observation i.e. LMN at that level of injury and UMN below is correct. For example also, weakness of the biceps with absence of the biceps reflex, with upper motor neuron signs in the legs suggests cord disease, possibly of discal origin at C5/6.

Reference 1