So aside from arguably the three most iconic characters in G1, the whole line is G1 accurate? Also, I think it just kinda comes down to using logic and looking at things case-by-case: Blaster coming with his cassettes is something no one would have an issue with. Blaster, much like Soundwave, is dominated by the cassette gimmick and always feels incomplete without them, yet unlike Soundwave doesn't come with at least one to utilize that. Even including Steeljaw would've at least been better than nothing, regardless of how it was back in the original G1 line. Starscream could've easily come without Megatron, but they knew it'd be more popular if he had that previously limited accessory. They even gave Optimus his two guns so fans could use whichever style they preferred. The deviations have been improvements, made to appeal to collectors in ways that make sense. Blaster could've easily come with a cassette and no one would consider it a compromise.