I don't really understand what you mean. Burning a year of the contract is not a choice made by the player or the team. It's automatic. The ELC may slide if certain criteria is met, most importantly the fact that a player is 18-19 years old when signing the ELC and doesn't turn 20 before the 31st of December in the year they signed.
Rantanen for an example, signed when he was 18 years old, then he only played in 9 NHL games (10 is the limit) before being sent down to San Antonio. This way, his ELC slided (sled, what is English?), and he still had 3 years with the Avs on his ELC before signing his first SPC in 2019.
Perreault, Demidov, Leonard etc, none of these players are slide eligible (too old). The first year of their ELC is burned off automatically upon signing, regardless if they play or not. So it would make sense to actually play them, especially in a situation where it matters f*** all if Perreault (or any other prospect in his position) looks lost out there because the team has nothing to play for.
I guess you can make the argument that teams want to burn off that year as well, because while the effective ELC is now two full seasons, the first "real" contract the player signs might be cheaper because they have proven less in the league. Regardless, the point I made above stands. There is literally nothing to be gained for sitting him in the pressbox.