In the first place, the letter also mentions
Happy Birthday Sidharth, so it was for the family letter task which coincided with Sids birthday. However it was irrelevant as the man wasnt in the house but in SR. In one way it does look genuine but it has raised many doubt's too.
Siddharth family never got involved or gave any statements via print media, IVs or SM handles till date.
In the past SBS had day out with Siddharth Shukla along with his mom.She had a typical South Mumbai look,.spoke well, not loud or harsh. At the same time grounded and presented herself well.
The Hindi and English mix does not match. Shuklas is from Allahabad who shifted to Mumbai. Let's give some credit to their Hindi.
Did expect a a letter even if hand written to be nicely presented on a A4 paper sheet.
What was difficult to digest is a statement written on the next page which states do not be the person which others want you to be ( provocation). It was zoomed many times for us to see
The letter does sound mysterious.