The 75% percent fill is for PTH for the lead not vias.

 The board design adds the metal thermal vias to help tranfer the heat to the 
pin you are trying to solder.
The extra metal vias are connected to the voltage or VCC layers, the solder 
adds nothing electrically beyond increasing reliability.

If you have a board with over 20 layers or 0.125 to 0.135" (3-3.5mm) thick 
board you will have a hard time getting good fill without the thermal vias to 
allow that area of the board to heat up. A thick board with only a large pad 
may lift up or the board will discolor from the heat. 
On the realy thick boards the lead protrusion is very little if any. 
The lead wicks up the solder as long as you haven't burnt up the flux prior to 
wave solder.

Side note: Solder in vias is only required for those vias used as test points and 
when the customer is using test fixtures that use vacuum to suck the board 
down against the test pins. Many new test fixtures and flying probe testers  
do not need vias to be soldered. Vias are often used as test points. When No-
Clean fluxes are used a stronger spring is required. The style of test probe is 
very important. 
 

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