Not by itself. Orientation to an employer's systems and procedures is ordinary and does not change the profession being performed. What matters is that the applicant already meets the listed profession's credential and that the position's substance is professional work rather than instruction. Where the answer stays unclear, look at what the employer has already sold: a client statement of work or project appointment naming the role responsible for the deliverables tells you more about the position's substance than the adjectives in an offer letter.
Separate learning the employer from learning the profession
A qualified engineer spending three weeks on internal tooling is learning an employer. Someone hired to be taught the profession over several months is describing a different arrangement, and that difference is what a reviewer will look at. Ask the employer which of the two the period is, in plain terms, and put a genuinely mixed answer in front of counsel before proceeding.
Two commercial records usually settle it. A signed statement of work or consultancy appointment shows whether the employer has committed the position to producing professional output on a live engagement during those opening weeks; a project programme shows on its face when that output falls due. Should both records place every deliverable after the training block, the honest reading is that professional work starts later, and that conclusion belongs in front of counsel before an application is prepared rather than after a refusal explains it.