Do cables that are not NM type need to be derated when used as NM?
Neither cable needs to be derated here, for multiple reasons

First off -- you only have one NM cable (the 14/2 W/G) in this hole, as the other cable (the 6-6-6-6) is a type SE cable; the two cables (NM and SE) are distinct in their constructions and usages, and are covered by different articles in the NEC (NM in Article 334, SE in Article 338).  As a result, the requirement in NEC 334.80 paragraph 2 that requires derating of multiple NM cables bundled through an insulation-packed hole in wood framing does not apply here to this situation, as there's only one NM cable to be had:


  Where more than two NM cables containing two or more
  current-carrying conductors are installed, without maintaining
  spacing between the cables, through the same opening in wood
  framing that is to be sealed with thermal insulation, caulk, or
  sealing foam, the allowable ampacity of each conductor shall
  be adjusted in accordance with Table 310.15(B)(3)(a) and the
  provisions of 310.15(A)(2), Exception, shall not apply.


Furthermore, this requirement only applies to sealed openings in wood framing; since your opening is unsealed, this passage would not apply even if you had 20 NM cables in the same opening.  Finally, this passage does not apply to SE cables anyway, as while SE cables are required to be treated as NM cables when used indoors by 338.10(B)(4)(a): 


  (a) Interior Installations. In addition to the provisions of
  this article, Type SE service-entrance cable used for interior
  wiring shall comply with the installation requirements of Part II
  of Article 334, excluding 334.80.
  
  For Type SE cable with ungrounded conductor sizes 10 AWG
  and smaller, where installed in thermal insulation, the ampacity
  shall be in accordance with 60°C (140°F) conductor temperature rating. The maximum conductor temperature rating shall
  be permitted to be used for ampacity adjustment and correction purposes, if the final derated ampacity does not exceed
  that for a 60°C (140°F) rated conductor.


, this passage explicitly excludes 334.80 from its requirements, as the wire insulation (often XHHW-2 or full THHN/THWN-2) on wires in SE cables is more robust than the PVC-only insulation used on the individual wires in a NM cable.