Is it a red flag to watch out for if a PS does not have any pics of explant without replacement? That's the procedure I need

Removal of breast implants is not generally considered an aesthetic procedure and I personally do not showcase pictures of implant removal on my website. The results are almost 100% patient factor dependent, so do not really feature my skill or artistry. There are also limits to how many before and after pictures we show on our websites, so these take away from pictures that do feature  more truly surgeon-dependent outcomes. 
That being said, if a patient would like to see pictures of an explantation, we can certainly show them in the office. However, you need to know that when it comes to explantation, another patient's photos won't give you much information regarding your own potential results. Again, this is because the outcome of implant removal is almost entirely dependent on patient factors such as age, skin quality, tissue thickness, under/over the muscle, presence/absence of some degree of capsular contracture, size of implants, etc. Lastly, showing patient photos requires consent. Patients having explantation procedures are far less likely to want their photos shared compared to those who have had augmentation procedures.
While I wouldn't necessarily judge your plastic surgeon for not showing you any pictures, you do need to have confidence that he/she is has the experience to know that your personal "patient factors" will allow for a good outcome. 

This is not a red flag per se, but it is important that you are comfortable and confident in your surgeon and surgical plan as you prepare for your procedure. I encourage you to speak to your surgeon about your concerns.

Thank you for sharing your question and best wishes on your upcoming surgery.  If you feel uncomfortable with your surgeon's ability to perform the procedure I would advocate seeking out second opinions.  I would also reach out to the surgeon directly to address your concerns as his RN may not have fully known what you were asking for or where she may find images.  Hope this helps.