Sure, today's Honor Code enforcement restrict more non-LDS kids, but I invite you to consider the following.

The stricter HC enforcement started before Lavell retired.

Most of Lavell's non-LDS recruits were NOT stars. These kids came to BYU because it was the best school to offer them. Please remember all the small JC DBs that played in those days. BYU needed those players, because the LDS base simply did not produce enough adequate recruits (and still falls a little short at WR/RB/DB). Lavell recruited a few non-LDS star HS players (e.g. Jamal Willis) and some low to medium HS recruits who developed into stars (e.g. Jimmy Mac/Leon White), but BYU most of the NFL quality players were LDS.

I think BYU's current crop of non-LDS players is as least as good a Lavell's average non-LDS recruit. The bigger pool of LDS kids available today more than compensates for the missing non-LDS kid of yesteryear. BYU still needs every TySon Williams and quality DB it can get, but most former 2-star non-LDS recruits can usually be replaced by LDS kids.