What do you mean by “will be”? Over a third of baby boomers are already dead. Even if it’s faster, demographic changes such as these are measured in months.
Yes, it is already a positive, but only a small positive. Not so much for medicare, because their big spend is in the last 6 months of life, and it doesn’t matter if the last 6 months are 83 and 2 months to 83 and 8 months versus 82 and 9 months to 83 and 3 months. For Social Security, think in terms of X% of SS recipients receiving $1,782.74 for 5 or 6 fewer months.