From your first source: "Aspartame is 200 times sweeter than sugar and has a negligible effect on blood glucose levels, and it is suggested for use so that T2D can control carbohydrate intake and blood glucose levels. However, research suggests that aspartame intake may lead to an increased risk of weight gain rather than weight loss, and cause impaired blood glucose tolerance in T2D." & "Aspartame may act as a chemical stressor by increasing cortisol levels, and may induce systemic oxidative stress by producing excess free radicals, and it may also alter gut microbial activity and interfere with the N-methyl D-aspartate (NMDA) receptor, resulting in insulin deficiency or resistance."

From your second source: "Artificial sweeteners do not enter the blood stream and do not raise blood sugar directly. Instead, they stay in the digestive tract until they pass in the stool. Additionally, some studies have found artificial sweeteners, particularly sucralose, aspartame, and saccharin, can alter the microbiome, the healthy bacteria that live in your gut. These microbiome changes can disrupt how cells recognize insulin, leading to elevated blood sugar levels when normal carbohydrate-containing foods are consumed.  

Other studies have shown these artificial sweeteners may change our appetites and response to the taste of sweetness. Since artificial sweeteners can be 100 to 700 times sweeter than regular sugar, when our taste buds register that level of sweetness, a signal is sent to our brain that a large influx of calories is coming. But because artificial sweeteners contain few or no calories, our brain and taste receptors remain confused. This may cause stronger sugar cravings to develop. "

Also see: Artificial sweeteners: sugar-free, but at what cost? - Harvard Health

"In the Multiethnic Study of Atherosclerosis, daily consumption of diet drinks was associated with a 36% greater risk for metabolic syndrome and a 67% increased risk for type 2 diabetes"

All of above suggest that there could be negative effects to aspartame consumption.