Not one bit of what he said is true; the only limitation is that you can't redo learning that you have already gained through other education routes, including apprenticeships, degrees, A-levels, etc.
For example, if you took Business for A-Levels and then wanted to do a Business Administration apprenticeship, then you wouldn’t be allowed. This is because the standard for Business Administration is a Level 3, and the A-Level you got in business is also a Level 3, so the learning aims will be roughly the same.
But, say you wanted to progress to do Business Management, then there wouldn’t be an issue as the qualification is of a higher level (Level 6/Degree), and the content involved in the course is completely different.
In your instance, you would probably be doing the Marketing Executive (Level 4). This wouldn’t then stop you from doing a higher-level standard such as Digital Marketer (Level 6) or Marketing Manager (Level 6). It also wouldn’t shorten the course either; they are completely different qualifications with their own learning outcomes.
The education levels are just something the government uses to benchmark and categorize qualifications. I will say not everyone needs to do a degree apprenticeship; there seems to be a big push on social media to do them for some reason. I've seen a few people do the marketing one and haven't needed to do the degree ones.
Each apprenticeship standard caters to a different set of roles. For example, the marketing executive one's typical roles will include Communications Executive, Communications Specialist, Marketing and Communications Officer, Marketing Executive, Marketing Officer, Marketing Specialist.