I started researching it and many people said that unless your child has a piano at home to practice (they said a keyboard isn't the same thing) then piano lessons aren't really a good idea.
Long ago, there were "manual" typewriters and "electric" typewriters, and each had a different reach and feel. Specifically, the rows of keys on a manual typewriter were more raised, and it took greater finger pressure to cause them to strike the ribbon. Yet, many children whose families had only a manual typewriter to practice on at home learned to type on an electric typewriter, through lessons at school.
Similarly, many children whose families have only an electronic keyboard to practice on at home, enjoy piano lessons. Some may say at this age it is better to let him try the piano lessons, practice on a keyboard, and see how far he'd like to pursue this interest. What he learns from piano lessons will benefit him in other areas.
ETA: Kids can change their interests quickly. Gifted kids have been known to change passionate, intense interests quickly.
