No. The actual role, qualifying employment and company relationship need factual support.
Identify what each statement establishes
A letter can explain evidence but should not claim authority, dates or ownership without a reliable basis. The title and tone do not replace the underlying facts.
A period of leave while remaining employed does not necessarily break continuity, but the qualifying year must consist of one continuous year of employment abroad within the three years before the petition. Managerial capacity means directing the organization or a component of it, supervising professional or supervisory staff, or managing an essential function; executive capacity means directing the company at a high level with wide discretion. Every L-1 case needs one continuous year of qualifying employment abroad within the prior three years, a qualifying parent, branch, subsidiary or affiliate, and continuing foreign business plus either active U.S. business or, for a new office, the ability to commence it. The transferee must also have worked abroad continuously for one qualifying year in the preceding three with a related organization, and the proposed US work must be primarily managerial or executive rather than routine production.