I would hope very much that any suggestions or contributions that you make are taken seriously and if a new colleague who was newly qualified arrived in my team, I would appreciate a fresh take on service delivery issues and welcome someone who takes an active interest in service improvement - even on their very first day.
Of course, it can depend on a team but I wouldn't want to work in any team where experienced colleagues (of which I suppose I should include myself, having been working for.. well, more than a few years!) were not receptive to someone offering new ideas and suggestions.