Antibiotic resistance has a fitness penalty. If we switch to this new antibiotic for long enough, bacteria may lose their resistance to our current antibiotics.
I'm assuming their suggestion is to use this drug for the next 30 years, and by the time bacteria become resistant to it we can start using our old antibiotics again.
Antibiotic resistance does not necessarily have a strong fitness penalty - the spread of community-resistant MRSA is largely in environments where there isn't strong selective pressure against susceptible strains.
I'm assuming their suggestion is to use this drug for the next 30 years, and by the time bacteria become resistant to it we can start using our old antibiotics again.