I think the main reason the new H50 has "survived" is because the competition on other channels on Friday night is mediocre, therefore it got good ratings.

Moving H50 to 8:00 p.m. this fall may affect this. This used to be the MacGyver time slot and I don't think that show did particularly well. According to one WWW site, "The third season of MacGyver [the one which just ended] averaged a 0.70 rating in the 18-49 demographic and 6.11 million viewers. Compared to season two, that’s down by 16% and 11%, respectively." The number of viewers was considerably less than those for H50: https://en.wikipedia.org/wiki/MacGyv...eries)#Ratings

Bringing MacGyver back is being held off until mid-season.

The H50 time slot at 9:00 will be taken over by the Magnum PI reboot. When this show was renewed for a second season (in January!), another WWW site commented that it "has improved its Monday time period in the ratings by +32%." Perhaps CBS thinks if they put Magnum in the 9:00 slot, it will do well, just like H50 did when it moved from Monday to Friday, though if you look at the ratings, that move did not particularly improve H50's viewership, but perhaps kept the number of viewers from declining -- https://en.wikipedia.org/wiki/Hawaii...eries)#Ratings