I just want to double-check but the week one update eliminates melta as a choice at creation for the weapons specialist, right?

Not entirely, because the Regiment could have meltaguns as a favored weapon. "Each regiment may choose one Basic weapon and one Heavy Weapon to be their Favoured Weapons,these weapons mat not have an Availability higher than Very Rare." Meltagun is now Very Rare, but still accessible under these rules and Weapon Specialists may take common craftsmanship favored basic weapons.

No. Because according to the update "Meltagun (page 125): In Table 6–9: Ranged Weapons, replace the Meltagun Availability with “Very Rare.”" so the regiment can choose Meltaguns as favored weapons and the weapon specialist can like before take one.

Edit: Too slow. What LuciusT said.

OK, thanks (both of you!).