Sorry man I wasn't having a go at you in particular, it's just a common talking point I see posted around various forums. More so the other post about this mod maker being a scammer just because he's charging for video content (which may not actually infringe on anyone's rights).
I've had first hand experience here. They do actually have the rights from WMS to use the Bally and Williams trademarks for pinball products (not for video games or slot machines), which includes doing a kind of sub-license deal with anyone who wants to make parts with those trademarks. The trademarks are registered and valid in both the UK and throughout Europe so anyone using them without a license can technically end up in jail if pursued.
But the reason why PPS don't make parts for so many games (like Johnny Mnemonic, Flintstones, Demo Man etc) is because they don't have the 3rd party licenses for those. There are often multiple licenses in place, multiple studios or publishers, including the right use an actors face or likeness and for this reason nearly all IP / Movie type games will never, ever have parts remade that are 'fully licensed' and 100% legit. It's either impossible to get the rights to them all or not financially viable.
Almost every product that CPR sells for example is unlicensed. They have the right to use Bally and Williams trademarks under PPS but that's it, they don't have the Data East license, or Star Wars, Star Trek, Playboy etc. Same goes for Classic Arcades, Pinball Centre, Ministry of Pinball etc, all the rest. It's all unlicensed. So it's kinda cringe when people on forums start screaming "OMG this random mod maker is uNliCeNsEd!!!!111!1".