Yes, not all DSDs involve XY chromosomes, or rather 46,XY chromosomes. Some DSDs involve 46, XX chromosomes. Other DSDs involve an unusual number of total chromosomes & atypical patterns of sex chromosomes, such as 45,X (Turner's syndrome) and 47, XXY (Klinefelter's).
Similarly, it's true as you say that "not every case of hyperandrogenism is caused by a DSD." Hyperandrogenism (HA) is a condition that occurs in female people with ovaries. Most HA is caused by polycystic ovary syndrome (PCOS), which is not a DSD.
The second most common cause of HA amongst people with female sex chromosomes is congenital adrenal hyperplasia or CAH, which is indeed considered a DSD. (BTW, CAH, both the classic salt-wasting kind apparent in infancy & the more common late-onset kind that emerges much later, accounts for the vast majority of all DSDs worldwide.)
But the current IAAF/WA DSD rules about eligibility in women's events do not apply to anyone with XX DSDs. They apply only to athletes with XY DSDs. What's more, they apply specifically to a subset of XY DSDs characterized by functioning testes, male levels of testosterone, & male-typical responsiveness to testosterone.
does this mean that any a female can have testosterone above 5nmol/L as long as they are not a "Relevant Athlete" who has one of the listed DSD's?
A female person with testosterone above 5 nmol/L would have serious health problems requiring urgent investigation & treatment by medical professionals.
These were knee-jerk rules introduced to block individuals without consideration for the implications.
Anyone who has followed the decades-long court cases in which XY DSD athletes have asserted their "right" to participate in women's sports would not describe the WA rules put in place in 2019 as "knee-jerk." Nor would they say these rules have been introduced "without consideration for the implications."