Unused Pokemon Type combinations

 Below are the list of Pokemon type combinations that is not used in the franchise's current video games.
01.) Normal/Ice
02.) Normal/Fire
03.) Normal/Electric
04.) Normal/Steel
05.) Normal/Rock
06.) Normal/Ground
07.) Normal/Dark
08.) Normal/Dragon
09.) Normal/Poison
10.) Normal/Ghost
11.) Normal/Bug
12.) Water/Fire
13.) Grass/Fire
14.) Grass/Electric
15.) Grass/Dragon
16.) Grass/Ghost
17.) Fire/Ice
18.) Fire/Poison
19.) Electric/Fighting
20.) Electric/Psychic
21.) Electric/Rock
22.) Electric/Dark
23.) Electric/Poison
24.) Flying/Fighting
25.) Fighting/Ghost
26.) Fighting/Dragon
27.) Fighting/Ice
28.) Fighting/Ground
29.) Psychic/Dark
30.) Psychic/Poison
31.) Psychic/Ghost
32.) Psychic/Bug
33.) Ice/Steel
34.) Ice/Rock
35.) Ice/Poison
36.) Ice/Bug
37.) Steel/Poison
38.) Steel/Ghost
39.) Rock/Dragon
40.) Rock/Poison
41.) Rock/Ghost
42.) Dark/Bug
43.) Dragon/Poison
44.) Dragon/Bug

153 possible type combinations, including the 17 mono-types... And as of now 649 pokemon were introduced (including the unofficial ones in the data), with 109 different type combinations.

Using my own math, assuming GameFreak introduces around 20 new type combinations each generation on average, it seems that the franchise is going to last for at least 2 more generations before they truly ran out of ideas. Probably new features to come?

Wonder would I still be interested in all this by then?