With the data you provided and assuming it will reaches 100th version, using Lagrange Interpolation, we can haveNothing wrong with the math you did, but there are some issues in your methods.
Your mistakes are in the initial assumption that there will be 88.5 more versions released before the game is complete, which is incredibly unlikely. Someone else already said this, but having all 100 version numbers (between 0.01.00 and 1.00.00) basically never happens.
You also made the mistake of a linear time between updates when extrapolating the future time between updates. Attached is the graph of the time between updates (I'm the one who posted the text version a few pages back.)
If we were to do the calculations to fit a formula for the time between updates and know (or guess) how many more updates there will be, and assume that future updates will follow the existing trend then we could redo your calculations (and would likely get a far worse time until the game is completed due to the rising time between updates).
This data brought to you by someone who overthinks the math and statistics, don't take it too seriously
f(x)=0.0000695822x^9−0.00411086x^8+0.105626x^7−1.54557x^6+14.1496x^5−83.7066x^4+318.362x^3−745.994x^2+973.633^x−535.25
and
f(100)=3.7624×10^13 (months)
which means this game would take about 3.1353×10^12 years to complete.