I would contain my "excitement" if I were you. The gap to the top 3, even though got shrunk, was still quite big by the end of 2019. They will have to gain ~1 second relative to the top 3 in order to fight for podiums. And when I say relative, that takes into the consideration the improvements the top 3 will make. So they probably need to make a step of ~1.5 seconds from last year to be in contention for podiums.
You really can't expect them to improve that much in one year's time. They did it from 2018 to 2019 because 2018 had a flawed car which was horrendous in every way imaginable. It was difficult to not improve from that point. The story is different this time around. It will be extremely hard to find anything more than 1 second for this season. And if they do find that second, it would be a huge achievement.
Also, Renault started closing in a little bit on the final races of 2019, especially on race pace. It is important to keep them at bay and secure another 4th place in the constructors. That's the realistic goal for 2020. Secure 4th again and be considerably closer to the top 3. If they do that, then we can all look for more from 2021 and beyond.