Seems like Welk (or somebody in his camp) commisioned arrangements specifically for the date, got some fine L.A. writers (Benny Carter among them, iirc) who understood the mutual requirements of such a meeting, let them do their thing, and, perhaps most importantly, treated Hodges like the royalty he was during the entire affair. Everybody was on the same page, and the results speak for themselves.
There's no polkas, no "la-la-la", "Calcutta"-type gimmick vocals, no typical Welk schmaltz, no anything other than Johnny Hodges as star of a very professionally arranged and performed mid-1960s type Easy-Listening album. It is what it is.