It is the standard form for older reels (and strathspeys, as noted by
John). Look at Vickers, or any older Scottish collection and that's
what you get.
The 8-bar form, before it became the more-or-less norm, was called
variously Hornpipe (undotted), Rant, Country Dance, or Scots Measure.
Soldier's Joy, for ex. was originally classed as a hornpipe. In the
Highland piping world tunes which to most ears would be reels (e.g.
Mason's Apron) are almost always called hornpipes, even today, if they
have repeated 8-bar strains.