They lowered the weight of streaming around this time last year as well (the week when Royals fell from #1).
The thing is, sales will keep decreasing and streaming will keep increasing, so they would probably have to adjust the formula every year to keep things balanced.
Also, they can't keep counting sales that high forever. When the #1s go back to selling 50,000 a week would they still want it to be counting for about 40% of the formula?
1D needs to take a break.
They've been releasing every year since 2011.
They're getting saturated.
Its not their decision to make. Their deal probably says album every year. Smart. You need to keep milking while they are hot. Its not gonna last very long.
It's close to be 1k Sales = 1M Airplay = 100k Streams but still some 2 points difference between Taylor/M5. Let's wait for full chart to start guessing. Another possible case is Sales*8 + Airplay*8 + Streaming*84