Ok, Ok, Ok. Let us first take the basic question of the OP.
The suit in question, according to reports (you always have to read them carefully, since reporters are rarely lawyers, and even more rarely have read the actual complaint filed), attempts to prevent the removal of the teen in question by asserting that he suffers from alchoholism, and is therefore entitled to continue play on the team, presumably under Section 504 of the Rehabilitation Act of 1973 (as amended in 1992 to conform with the provisions of the ADA), which requires that recipients of federal funds not discriminate against disabled people. Public schools are often subject to Section 504.
Alchoholism can be a ‘disability’ under the ADA and, therefore, under Section 504. A ‘disability’ is “a physical or mental impairment that substantially limits one or more major life activities.” The American Psychiatric Association continues to list alchoholism as a diagnosable condition in its Diagnostic and Statistical Manual (4th Rev.) Courts have consistently (so far as I know) found alchoholism to be a disability under the ADA. This was true prior to ADA under the Rehabilitation Act (see e.g. Rogers v. Lehman (1989) 869 F.2d 253).
Now the trouble with the suit, frankly, is in equating the removal from the team with discrimination over alchoholism. The school district will, undoubtedly, assert that the reason the player was removed was his illegal conduct (Driving While Intoxicated). To establish that the disability neutral policy of the district should be set aside because it happens to have a bad result for a teen with alchoholism isn’t in accord with prior decisions on neutral policies. Further, it is doubtful a court would equate alchoholics with DWI - an alchoholic is certainly able to avoid driving intoxicated.
As for the other part of the thread, regarding whether alchoholism is or is not a disease - please, if you are going to discuss this, at least make yourself familiar with the evidence on the subject. Ranting about how it isn’t a disease just cause people can ‘stop’ isn’t productive.