There are no doubt some who would be resistant to preaching about sin for six whole weeks (seven, since she includes Easter!), reclaimed or otherwise—though I suspect that these days, this mainline stereotype is not so terribly widespread. In any case, I'm at least as interested in the prospect of an RCL preacher sticking with the OT for that long. Some of course do this routinely; many do not. One of the arguments for the Narrative Lectionary, which assigns a single preaching text each week, is that the best way to get preachers into the OT is to simply eliminate other options. In any event, I'm always excited to hear a sermon on the OT, so I hope others try Hackenberg's series or something similar.
If you have series ideas for Lent this year, I'd be glad to hear them—especially if you're basing the series on lectionary texts, RCL or otherwise.