No. Completion of an approved basic training course under point 147.A.200 in a Part-147 approved maintenance training organisation is not the only route to obtaining an Aircraft Maintenance Licence (AML).
The basic knowledge requirements may be met by successfully passing examinations in accordance with point 66.A.25. These examinations may be conducted by a Part-147 organisation, the competent authority or, in the case of category L, by another organisation accepted by the competent authority.
However, completion of an approved basic training course at a Part-147 approved maintenance training organisation allows the required basic experience to be reduced in accordance with point 66.A.30, provided that the conditions of that provision are met. Reference: 66.A.25, 66.A.30(a) and 147.A.200.