The short answer is “yes” - DEFINITELY yes. Although law school may seem a long time away, many firms will not even consider your application complete – and hence will not begin to review it – unless they have your transcript on file.
Indeed, sometimes firms even request law school transcripts from partner candidates. I am working with one candidate in particular who is applying to a top firm and was hesitant to submit her law school transcript. She had stellar grades her first year in law school, which put her in a great position for second year on-campus interviewing and thus she snatched up a coveted summer associate position at a top firm. Her grades then went down significantly during her last two years in law school, but she received a permanent offer at the firm where she summered and has practiced there ever since. This candidate is concerned that submitting her transcript will hurt her chances.
Although it is true that some firms are very strict on grades - the fact that she works at a top firm and went to a top law school will, for many firms, be the definitive factors. And although there are some firms that will not want consider hiring her or even bringing her in for an interview due to her final law school GPA, without a transcript she wouldn’t be considered at all.