Hi Kiwi26,
You can read a little more about “textiles fiber waste of unknown kind” here and here. It’s basically a mix of cloth scraps and leftovers from various sources that have been shredded. It’s “unknown” because it contains many different types of fibers so it can’t be labelled as one or the other.
There would be nothing wrong with sleeping on a mattress that contained this if it was new material (the law tag should say if it’s new material) and the mattress as a whole was suitable in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences). To me it’s an innovative use of a low cost source material.
Your mattress appears to use different materials though (you mentioned it’s a latex mattress) so it may be a moot point anyway. A mattress is only as good as the quality of its construction and the materials inside it in terms of durability and value regardless of who makes it so knowing the materials inside the mattress you are considering would be be much more important than the materials used in other mattresses they make.
If the mattress is suitable for your needs and preferences (and you have done careful and objective testing for PPP along the lines of the guidelines in post #1 here) and it uses good quality and durable materials and is good value compared to other similar mattresses that have a similar design then that would be among the most important parts of most people’s personal value equation.
It’s always very important of course to make sure you test a mattress for your specific needs and preferences and then also find out the details of all the layers inside it so you can make meaningful comparisons with other mattresses and make more informed buying decisions.
Some of the better options and possibilities I’m aware of in the Los Angeles area are listed in post #2 here.
Phoenix