Then he can most certainly void or cancel the lease based upon that was of utmost importance in his selection of an apartment to rent and they are not providing such. In fact, it would appear that it's an impossibility for them to provide such currently.
If the fact that they were/are to provide internet services and can't - that alone is a legal reason and basis for him to declare the lease void and notice them that he's vacating.
That he would not have rented the apartment "but for" the ability to have and the landlord to supply internet services.
That is a major deficiency which allows him to declare the lease canceled and/or breached by the landlord.
I would have him take pictures of the apartment before he leaves to CYA in case they want to charge him for the carpeting, the water damages
But, yes most definitely he can void the lease.
Now if the internet was incidental he would only be able to get reduction - not void the lease. For example a grandmother leasing the space when it's not a needed service could not void the lease but get reduction of rent.
Your son, on the other hand can void the lease.
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