True but they both use microcode to control their defaults. I understand Intel fix their microcode to close the exploit in future Xeon V5. Due to defaults and thus micro code in the broadwell-LP has changed could their be exploits for board makers?You're talking completely different platforms. Broadwell is simply a die shrink of Haswell. Skylake is only on the LGA1151 socket right now. We haven't seen the Skylake successor to LGA2011-3 yet.
If you dropped an E5v4 Xeon in here, yes, you could OC it using BCLK just like you could with all other Sandy Bridge, Ivy Bridge, or Haswell Xeons. However, Broadwell doesn't change the BCLK like Skylake does, so you'd likely only be able to get a 5% OC.