as long as new calyx's and hairs are being produced there is still weight and resin being produced and trichomes to mature, terpenes to develop, etc. some pure sativas (or at least heavily dominant) ive read will keep pushing new hairs all the time.
you said you are a couple weeks from harvest but havent mentioned how many days they have actually been flowering for. if you are on like day 42 and expecting to finish on day 56 (8 week flower) theyll probably be immature still or just barely opening the harvest window. i usually wait until most of the hairs have turned (like 80%) before i look at trichomes and a ton of new ones will come during the next week, 2 sometimes, putting on a bit more weight for the final swell.
i think the plant looks good but has a little way to go. i suppose you could harvest some now and some later just to see the differences and ive done it to and found i was harvesting too early not only losing out on weight but potency as well but its a good experiment to do at least once just so you know and you could also let one go way longer than necessary to see how the plant dies by natural causes.